PHP Login System with PDO Connection

Very long back, we had published a simple PHP login system using PHP, which works only with MySQL database. Today, we are providing you an easy registration and login process using PDO connection with better password encryption, which has an advantage of working on different database systems. PDO is a PHP extension that allow us to implement code which is portable across many databases and platforms. This registration process is used in Wall Script 8. Here is the demo of this cool & simple login / registration process.

Users Table

User table contains all the users registration details.

CREATE TABLE `users` (
`uid` int NOT NULL PRIMARY KEY AUTO_INCREMENT ,
`username` varchar(25) NOT NULL UNIQUE,
`password` varchar(50) NOT NULL ,
`email` varchar(100) NOT NULL,
`name` varchar(100) NOT NULL,
`profile_pic` varchar(200) NOT NULL,
);

Enable PDO extension for PHP, find this in php.ini configuration file.

config.php
Database connection configuration file, here you have to modify username, password and database details. If you are using other database modify PDO() driver connection value.

<?php
session_start();
/* DATABASE CONFIGURATION */
define('DB_SERVER', 'localhost');
define('DB_USERNAME', 'username');
define('DB_PASSWORD', 'password');
define('DB_DATABASE', 'databasename');
define("BASE_URL", "http://localhost/PHPLoginHash/"); // Eg. http://yourwebsite.com

function getDB()
{
$dbhost=DB_SERVER;
$dbuser=DB_USERNAME;
$dbpass=DB_PASSWORD;
$dbname=DB_DATABASE;
try {
$dbConnection = new PDO("mysql:host=$dbhost;dbname=$dbname", $dbuser, $dbpass);
$dbConnection->exec("set names utf8");
$dbConnection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
return $dbConnection;
}
catch (PDOException $e) {
echo 'Connection failed: ' . $e->getMessage();
}

}
?>

HTML Login Form
Contains simple HTML code.

<div id="login">
<h3>Login</h3>
<form method="post" action="" name="login">
<label>Username or Email</label>
<input type="text" name="usernameEmail" autocomplete="off" />
<label>Password</label>
<input type="password" name="password" autocomplete="off"/>
<div class="errorMsg"><?php echo $errorMsgLogin; ?></div>
<input type="submit" class="button" name="loginSubmit" value="Login">
</form>
</div>

 

HTML Signup Code
User registration page.

<div id="signup">
<h3>Registration</h3>
<form method="post" action="" name="signup">
<label>Name</label>
<input type="text" name="nameReg" autocomplete="off" />
<label>Email</label>
<input type="text" name="emailReg" autocomplete="off" />
<label>Username</label>
<input type="text" name="usernameReg" autocomplete="off" />
<label>Password</label>
<input type="password" name="passwordReg" autocomplete="off"/>
<div class="errorMsg"><?php echo $errorMsgReg; ?></div>
<input type="submit" class="button" name="signupSubmit" value="Signup">
</form>
</div>

 CSS Code

#login,#signup{
width: 300px; border: 1px solid #d6d7da;
padding: 0px 15px 15px 15px;
border-radius: 5px;font-family: arial;
line-height: 16px;color: #333333; font-size: 14px;
background: #ffffff;rgba(200,200,200,0.7) 0 4px 10px -1px
}
#login{float:left;}
#signup{float:right;}
h3{color:#365D98}
form label{font-weight: bold;}
form label, form input{display: block;margin-bottom: 5px;width: 90%}
form input{
border: solid 1px #666666;padding: 10px;
border: solid 1px #BDC7D8; margin-bottom: 20px
}
.button {
background-color: #5fcf80 ;
border-color: #3ac162;
font-weight: bold;
padding: 12px 15px;
max-width: 100px;
color: #ffffff;
}
.errorMsg{color: #cc0000;margin-bottom: 10px}

userClass.php
This class contains there methods userLogin, userRegistion and userDetails.

<?php
class userClass
{
/* User Login */
public function userLogin($usernameEmail,$password)
{
try{
$db = getDB();
$hash_password= hash('sha256', $password); //Password encryption 
$stmt = $db->prepare("SELECT uid FROM users WHERE (username=:usernameEmail or email=:usernameEmail) AND password=:hash_password");
$stmt->bindParam("usernameEmail", $usernameEmail,PDO::PARAM_STR) ;
$stmt->bindParam("hash_password", $hash_password,PDO::PARAM_STR) ;
$stmt->execute();
$count=$stmt->rowCount();
$data=$stmt->fetch(PDO::FETCH_OBJ);
$db = null;
if($count)
{
$_SESSION['uid']=$data->uid; // Storing user session value
return true;
}
else
{
return false;
}
}
catch(PDOException $e) {
echo '{"error":{"text":'. $e->getMessage() .'}}';
}

}

/* User Registration */
public function userRegistration($username,$password,$email,$name)
{
try{
$db = getDB();
$st = $db->prepare("SELECT uid FROM users WHERE username=:username OR email=:email");
$st->bindParam("username", $username,PDO::PARAM_STR);
$st->bindParam("email", $email,PDO::PARAM_STR);
$st->execute();
$count=$st->rowCount();
if($count<1 stmt="$db-">prepare("INSERT INTO users(username,password,email,name) VALUES (:username,:hash_password,:email,:name)");
$stmt->bindParam("username", $username,PDO::PARAM_STR) ;
$hash_password= hash('sha256', $password); //Password encryption
$stmt->bindParam("hash_password", $hash_password,PDO::PARAM_STR) ;
$stmt->bindParam("email", $email,PDO::PARAM_STR) ;
$stmt->bindParam("name", $name,PDO::PARAM_STR) ;
$stmt->execute();
$uid=$db->lastInsertId(); // Last inserted row id
$db = null;
$_SESSION['uid']=$uid;
return true;
}
else
{
$db = null;
return false;
}

}
catch(PDOException $e) {
echo '{"error":{"text":'. $e->getMessage() .'}}';
}
}

/* User Details */
public function userDetails($uid)
{
try{
$db = getDB();
$stmt = $db->prepare("SELECT email,username,name FROM users WHERE uid=:uid");
$stmt->bindParam("uid", $uid,PDO::PARAM_INT);
$stmt->execute();
$data = $stmt->fetch(PDO::FETCH_OBJ); //User data
return $data;
}
catch(PDOException $e) {
echo '{"error":{"text":'. $e->getMessage() .'}}';
}
}
}
?>

index.php
Contains PHP and HTML code, works base on user form submit.

<?php
include("config.php");
include('class/userClass.php');
$userClass = new userClass();

$errorMsgReg='';
$errorMsgLogin='';
/* Login Form */
if (!empty($_POST['loginSubmit']))
{
$usernameEmail=$_POST['usernameEmail'];
$password=$_POST['password'];
if(strlen(trim($usernameEmail))>1 && strlen(trim($password))>1 )
{
$uid=$userClass->userLogin($usernameEmail,$password);
if($uid)
{
$url=BASE_URL.'home.php';
header("Location: $url"); // Page redirecting to home.php 
}
else
{
$errorMsgLogin="Please check login details.";
}
}
}

/* Signup Form */
if (!empty($_POST['signupSubmit']))
{
$username=$_POST['usernameReg'];
$email=$_POST['emailReg'];
$password=$_POST['passwordReg'];
$name=$_POST['nameReg'];
/* Regular expression check */
$username_check = preg_match('~^[A-Za-z0-9_]{3,20}$~i', $username);
$email_check = preg_match('~^[a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.([a-zA-Z]{2,4})$~i', $email);
$password_check = preg_match('~^[A-Za-z0-9!@#$%^&*()_]{6,20}$~i', $password);

if($username_check && $email_check && $password_check && strlen(trim($name))>0)
{
$uid=$userClass->userRegistration($username,$password,$email,$name);
if($uid)
{
$url=BASE_URL.'home.php';
header("Location: $url"); // Page redirecting to home.php 
}
else
{
$errorMsgReg="Username or Email already exists.";
}
}
}
?>
//HTML Code
....Login Form HTML Code....

....Signup Form HTML Code...

Note: You have to include JavaScript validations for better user experience.

session.php
This will validate and store user session value.

<?php
if(!empty($_SESSION['uid']))
{
$session_uid=$_SESSION['uid'];
include('class/userClass.php');
$userClass = new userClass();
}
if(empty($session_uid))
{
$url=BASE_URL.'index.php';
header("Location: $url");
}
?>

home.php
User welcome page, display user details base on user session value.

<?php
include('config.php');
include('session.php');
$userDetails=$userClass->userDetails($session_uid);
?>
<h1>Welcome <?php echo $userDetails->name; ?></h1>

<h4><a href="<?php echo BASE_URL; ?>logout.php">Logout</a></h4>

logout.php
This code will clear user session values.

<?php
include('config.php');
$session_uid='';
$_SESSION['uid']='';
if(empty($session_uid) && empty($_SESSION['uid']))
{
$url=BASE_URL.'index.php';
header("Location: $url");
//echo "<script>window.location='$url'</script>";
}
?>

 

Credit to 9lession

Apple fixes iPhone 6S flaw allowing anyone access to contacts and photos

Apple fixes iPhone 6S flaw allowing anyone access to contacts and photos And you don't even need to update your software
APPLE HAS BEEN QUICK to fix an issue that let anyone access contacts on photos on a locked iPhone 6S or 6S Plus.
In a statement to the Washington Post, Apple confirmed that the bug was fixed, without users' having to update their software. Again.
Just days after releasing iOS 9.3.1 to fix the link-crashing glitch plaguing iPhones and iPads, it was discovered that a bug in the software allowed anyone to access photos and contacts on a locked device.
A YouTube video (below) shows the vulnerability in action and reveals that all a hacker needs to pilfer contacts from a passcode-locked iPhone 6S or 6S Plus is access to Siri and 3D Touch.
The hack proved worryingly easy to execute. You simply fire up Siri by pressing the home button or the 'Hey Siri' command, and ask Apple's mouthy digital assistant to initiate a Twitter search. If the results include contact details such as an email address, using 3D Touch on the contact information will bring up the Quick Actions Menu and allow you to add it to an existing contact - in turn offering access to the iPhone's entire contacts list.
What's more, by selecting a contact and choosing to add an image, the iPhone's entire photo library can be accessed.
As Siri could carry out the command in question only if given permission to access Twitter account information, as well as contacts and photos, a quick fix was discovered. To revoke these permissions, head to Settings > Privacy and switch off Siri's access to Twitter and Photos. To stop it accessing your contacts, you'll need to disable Siri's lock screen activation by heading to Settings > Touch ID & Passcode.
The link-crashing glitch and new Siri and Touch ID flaw aren't the only problems that have bothered early iOS 9.3 adopters.
The firm was forced to release yet another update to fix a bug plaguing users of older Apple devices who reported that the update turned their iPhone and iPad into an expensive lump of metal and glass. µ
To hear more about security challenges, the threats they pose and how to combat them, sign up for The INQUIRER sister site Computing's Enterprise Security and Risk Management conference taking place on 24 November.

Credit to theinquirer

Ubuntu Patches Linux Kernel Security Bugs

An Ubuntu update released on Wednesday fixes bug in a Linux kernel driver that could be used to take control of a machine.
Canonical has released an update that patches four bugs that, including one that could cause an attacker to execute code.
Ubuntu users have been notified of a reasonably pressing update to install that addresses four security issues, though none are remotely exploitable. The bugs affect Ubuntu 14.04 Long Term Support (LTS), which gets five years of coverage.
The most serious is a use-after-free flaw in a Linux kernel driver. The medium priority bug, found by Venkatesh Pottem last year, could allow a local attacker to cause a system crash and may allow them to execute code on the system.
"A flaw was found in the CXGB3 kernel driver when the network was considered congested. The kernel would incorrectly misinterpret the congestion as an error condition and incorrectly free/clean up the skb. When the device would then send the skb's queued, these structures would be referenced and may panic the system or allow an attacker to escalate privileges in a use-after-free scenario," Canonical notes in an advisory.
It also fixes a low-priority timing side-channel vulnerability in the Linux Extended Verification Module, which an attacker could use to compromise system integrity.
A local attacker could also trigger a denial-of-service due to the Linux kernel incorrectly accounting file descriptors. This is considered a medium priority issue.

The fourth issue, a low priority, could also be used to cause a denial-of-service due to the Linux kernel not enforce limits on the data allocated to buffer pipes.
The references for the bugs are CVE-2015-8812, CVE-2016-2085, CVE-2016-2550, CVE-2016-2847.

FBI paid for the Apple iPhone key, says director James Comey

Probably got it off the internet MAN YOU CAN TRUST, FBI director James Comey, has revealed that the infamous means of getting into a locked Apple iPhone was a paid-for solution.
He went pretty mum after that. Comey delivered the revelation during a Q&A session at Kenyon College in Ohio, according to a report on Fox News. We have asked the FBI to confirm this, but our email does not seem to be getting through to the organisation. We cannot help feeling that this is ironic.
Comey's comments suggest that all parties will toe this line and that no-one will break cover and reveal the who and the how. Perhaps he hasn't heard of the internet.
"The people that we bought this from, I know a fair amount about them and I have a high degree of confidence that they are very good at protecting it, and their motivations align with ours," he said, according to Fox News.
This does not confirm or deny that the source is the Israeli company Cellebrite that we all thought it was, or squash any speculation from at least one wild eyed dude that it was the ghost of Steve Jobs riding a unicorn that did it.
Unless magic was involved we are going to assume that software was the solution to the FBI's phone problem. The department is obviously making the most of it, as it is already offering to unlock iPhones on demand via its Little Rock field office for a case in Arkansas.
However, Comey admitted that the tool does not work on all iPhone models. "This doesn't work on [an iPhone] 6S, doesn't work on a 5S, and so we have a tool that works on a narrow slice of phones," he said.
Those other models probably cost extra to unlock.

 

FBI director says government 'purchased a tool' to access San Bernardino gunman's phone 

The head of the FBI said Wednesday that the government had "purchased a tool" enabling investigators to access an iPhone belonging to San Bernardino gunman Syed Farook.
The disclosure by James Comey in a speech at Ohio's Kenyon College was a departure from previous official statements, which had been vague in explaining the details of how the government broke into the phone last month.
The Justice Department had only said that a third party had "demonstrated" an alternate method of unlocking the device to the FBI the evening before federal prosecutors filed a motion to delay a court hearing on the matter.
"The people that we bought this [tool] from – I know a fair amount about them and I have a high degree of confidence that they are very good at protecting it, and their motivations align with ours," Comey said during a question-and-answer period following his talk.
Comey added that the technology only works on an iPhone 5C, the type of phone used by Farook.
"This doesn’t work on [an iPhone] 6S, doesn’t work in a 5S, and so we have a tool that works on a narrow slice of phones," he added.
Neither the Justice Department nor the FBI could immediately provide further details.
The exact method the FBI used to access information on Farook's phone is a mystery that has puzzled Apple software engineers and outside experts alike. After the FBI hacked into the phone, Magistrate Judge Sheri Pym vacated her order compelling Apple to assist the FBI in hacking their phone, which also took away any obvious legal avenues Apple might have used to learn how the FBI did it.
A senior law enforcement official told The Associated Press last month that the FBI managed to defeat an Apple security feature that threatened to delete the phone's contents if the FBI failed to enter the correct passcode combination after 10 tries. That allowed the government to repeatedly and continuously test passcodes in what's known as a brute-force attack until the right code is entered and the phone is unlocked.
It wasn't clear how the FBI dealt with a related Apple security feature that introduces increasing time delays between guesses.
At the time, Comey said with those features removed, the FBI could break into the phone in 26 minutes.
Farook died with his wife in a gun battle with police after they killed 14 people Dec. 2 in San Bernardino, Calif. The iPhone, issued to Farook by his employer, the county health department, was found in a vehicle the day after the shooting.
A senior FBI official told The Wall Street Journal Tuesday that investigators were still analyzing the phone and had not decided whether to disclose what they had found.
Fox News' Matthew Dean and the Associated Press contributed to this report.
 

Credit to theinquirer

Oracle demands $9.3bn from Google over Java APIs in Android

Next round in long-running court action due to kick-off in April

Oracle is demanding damages of $9.3 billion from Google in its intellectual property dispute against the company over the Android operating system.
The demand is the latest chapter in the long-running disagreement between the two companies over the Dalvik Java virtual machine (JVM) used to run apps on the Android operating system up to version 4.4, also known as KitKat.

Oracle has argued that although Java is open source the APIs required to use it aren't. Google is perfectly entitled to use Java in Android, but Google must pay Oracle a generous licence fee for doing so.
Oracle filed suit against Google in August 2010 and Dalvik was subsequently replaced by the Android Runtime, which compiles Android apps to native machine code upon installation, circumventing Oracle's Java API intellectual property claims.

The court case, however, goes on. 

The arguments against Oracle's stance in the industry have been far-reaching, including claims that it could set a precedent that would wipe the premise of open-source software off the map, at least as we know it today.

Notwithstanding this, however, Oracle has claimed that Android has "destroyed" the Java market, while Google maintains that APIs constitute "fair use". Google has won twice, and Oracle has successfully appealed twice, making way for the current action.
Oracle wants $475m damages and an $8.83bn profit share of Android from 2010 up to Lollipop. Marshmallow, the current version of the OS, is not included in the action.
Google has said that even if it is guilty, the code infringement of 37 APIs represents a tiny amount of the overall codebase, and the figure it has in mind is more like $100 million at most. It will nevertheless fight tooth and nail against it anyway.
A pre-trial hearing is set for 27 April and the trial itself will start on 9 May.
Google has already lost a battle to take the matter to the Supreme Court, despite feeling that judges in the earlier trial didn't understand the subject matter on which they had to rule.

As ever, there is no guarantee that whatever decision is made will be the final chapter. Appeal and counter-appeal will continue for some time before US law is actually clarified. 

Oracle's victory over Google Android could kill the software industry 

EVERYTHING you've ever coded could now be in breach of US law. However melodramatic that sounds, it's chillingly accurate.
The recent ruling clearing Oracle to pursue Google for lines of its Java code hidden at the heart of its all-conquering Android mobile operating system spells big trouble for every software developer who has ever relied upon supposedly open-source code in their own software.

The recent appeal overturned a 2012 ruling in favour of Google's right to the use of open-source code. As a result, Oracle is now free to chase Google over royalties for the billions of devices around the world that work because the Java APIs, which the web firm assumed were open source, are now considered protected under copyright.
Although there is bound to be more legal wrangling before the decision becomes final, the precedent set by the case should send a cold shiver down the spine of every developer who has ever taken advantage of the swathes of open-source code available as software interface APIs.
Oracle's successful argument is that while you are welcome to use its code, the APIs, the interfaces that allow it to function with your own, are subject to copyright. Therefore, if anything worth pursuing comes of your own coding project, Oracle owns a slice.
Oracle argues that an API is more than just a functional piece of code devoid of creativity and therefore is copyrightable as is, and therefore anyone using the code to their own ends is infringing the database firm's copyright.
Simply put, the ruling sets the precedent that you are welcome to use the open-source code, it's free, but you have to pay to access it in the first place. It's a little bit like going to a lending library, but being charged a hefty rental fee to borrow a book.
Google's response showed it isn't ready to roll over yet. It said, "We're disappointed by this ruling, which sets a damaging precedent for computer science and software development, and are considering our options."
Indeed Google's options include requesting that the appeal be reconsidered by the entire appeals court instead of the three judge panel that overturned the original ruling. Google also has the eventual option of seeking an appeal to the US Supreme Court.
As things stand, the next hearing will be on remand back to the US District Court to decide if Google's embedding of Java code is warranted as Fair Use, or whether damages and royalties, which might be considerable, are payable to Oracle.
Even if Google's use of the Java APIs in Android is found to be Fair Use, the demands made by Oracle could still impact innovation across the software development industry. Many of the best ideas come from bedroom developers taking advantage of open-source APIs. Now those same developers might not be able to use those same lines of code without a team of lawyers on standby.
But it's worse than that. In the IT industry, everything connects. If Oracle's lawyers can establish that the Java APIs are protected by copyright, then so can anyone's lawyers. If you wanted to find a holiday destination, find out the weather, book a rental car, renew your passport and learn some basic phrases, you could be interfacing with 15 to 20 APIs. If each of the copyright holders decides to charge for or forbid access to those APIs, then nothing will work. The whole software industry - indeed the whole internet - will fail.
The fundamentals here are simple - either something is open source, or it isn't. Oracle seems to be trolling for reparations over code that it didn't even develop, but rather bought via its acquisition of Sun Microsystems, merely because there is opportunity, and that goes against the very spirit of open source. Because the appeals court judges that wrote the ruling failed to understand the repercussions of what they've done, it could decimate the IT industry if left to stand.

Oracle claims Google has used Android to 'destroy' the Java market 
World's smallest violin discovered at Mountain View offices
ORACLE HAS ADDED more allegations to its court filing against Google, claiming that it has "destroyed" the market for Java.
The case stems from the use of Java libraries in the original Android operating system design. While these are open source, a clueless judge ruled that the APIs allowing third parties to use the libraries are subject to copyright and it is those libraries which Google is accused of infringing.

As regular readers will know, we have labelled this what in journalistic circles we like to refer to as 'a heap of old horse shit' that sets a dangerous precedent for the whole industry. However, Oracle is continuing to glove-slap for satisfaction.
The latest papers filed, which Google is yet to contest the addition of, work best if dictated with a single violin playing sombrely in the background.
"Although all of these new Android versions are dependent upon the infringing Java code, applications written for these new Android versions are not compatible with the Java platform, because they do not run on the Java platform or on devices implementing the Java platform," the filing said.
"Similarly, applications written for the Java platform do not run on the versions of Android made available since October 2010. Accordingly, given the widespread dominance Android has achieved with its continued unauthorised use of the 37 Java API packages over the past few years, Android has now irreversibly destroyed Java’s fundamental value proposition as a potential mobile device operating system by breaking the 'write once, run anywhere' principle on which Java was built.
"Google’s increasing domination of the mobile device market with Android, and its continuing failure and refusal to make Android compatible with the Java platform, has destroyed the potential value of a licensed derivative version of the Java platform in the mobile device market."
Cutting to the chase, what Oracle is basically saying is that Google used them, then spat them out, leaving them unappealing to others, which makes them sound like a fallen woman in a Thomas Hardy novel.
The defence is likely to be that Java is an ageing, exploit-ridden system that has to be regularly patched up, and that forking from it was the best thing to do for customers. But, as ever with these epic battles, it's going to be down to who has the best lawyers. Or the biggest yacht.
Oracle argues that the meteoric rise of the Android platform, and its market dominance, based on thousands of lines of Java code and yielding billions in ad revenues, means that the Ellison yachting fund is due a top-up.
Google has consistently claimed that, even if the APIs are copyrightable, 'fair use' is at play. Twice the court has sided with Google, and twice the decision has been overturned on appeal by old men who probably smoke cigars but think that the World Wide Web gives you cancer.

Appeals court rules Google infringed Oracle's Java copyright in Android 
If at first you don't succeed, troll and troll again

THE UNITED STATES Court of Appeals for the Federal Circuit has remanded the copyright infringement lawsuit between Oracle and Google back to the US District Court for the Northern District of California.
The action was brought in 2010 over copyright to the portions of code in the Android mobile operating system that are based on Java APIs owned by Oracle.
The move paves the way for Oracle to further pursue its demands that Google pay for the API code, which US District Court Judge William Alsup had previously ruled at trial was not copyright protectable.
"We conclude that a set of commands to instruct a computer to carry out desired operations may contain expression that is eligible for copyright protection," Federal Circuit Court of Appeals Judge Kathleen O'Malley wrote.
The ruling could be a game-changer for the US software industry, with programmers facing uncertainty about whether they can create inter-operable software using APIs, and possibly having to consult teams of lawyers just in case there are trolls under the bridge.
Google understandably is not pleased. A spokesperson told The INQUIRER in a statement, "We're disappointed by this ruling, which sets a damaging precedent for computer science and software development, and are considering our options."
Oracle brought the case against Google, seeking $2.2bn for its alleged share of the world's biggest mobile operating system. Google offered to settle, but Oracle turned down the deal for $2.8m, leaving it with a $4m legal bill after the court found in Google's favour in 2012.

Although things went quiet for a while, save for a report that court papers showed Android as being less open than it claimed, Oracle's appeal continued and led to this ruling.

While Oracle CEO Larry Ellison will doubtless be delighted with a result that might net the company a large judgment, and let it join Microsoft in earning a cut of every Android device sold, the motives of a man who ditched his keynote at his own conference last year to go play with boats remain a bit mysterious.

Credit to computing

The Free Software Definition

The Free Software Definition

The free software definition presents the criteria for whether a particular software program qualifies as free software. From time to time we revise this definition, to clarify it or to resolve questions about subtle issues. See the History section below for a list of changes that affect the definition of free software.

“Free software” means software that respects users' freedom and community. Roughly, it means that the users have the freedom to run, copy, distribute, study, change and improve the software. Thus, “free software” is a matter of liberty, not price. To understand the concept, you should think of “free” as in “free speech,” not as in “free beer”. We sometimes call it “libre software” to show we do not mean it is gratis.
We campaign for these freedoms because everyone deserves them. With these freedoms, the users (both individually and collectively) control the program and what it does for them. When users don't control the program, we call it a “nonfree” or “proprietary” program. The nonfree program controls the users, and the developer controls the program; this makes the program an instrument of unjust power.
A program is free software if the program's users have the four essential freedoms:

• The freedom to run the program as you wish, for any purpose (freedom 0).
• The freedom to study how the program works, and change it so it does your computing as you wish (freedom 1). Access to the source code is a precondition for this.
• The freedom to redistribute copies so you can help your neighbor (freedom 2).
• The freedom to distribute copies of your modified versions to others (freedom 3). By doing this you can give the whole community a chance to benefit from your changes. Access to the source code is a precondition for this.

A program is free software if it gives users adequately all of these freedoms. Otherwise, it is nonfree. While we can distinguish various nonfree distribution schemes in terms of how far they fall short of being free, we consider them all equally unethical.
In any given scenario, these freedoms must apply to whatever code we plan to make use of, or lead others to make use of. For instance, consider a program A which automatically launches a program B to handle some cases. If we plan to distribute A as it stands, that implies users will need B, so we need to judge whether both A and B are free. However, if we plan to modify A so that it doesn't use B, only A needs to be free; we can ignore B.
The rest of this page clarifies certain points about what makes specific freedoms adequate or not.
Freedom to distribute (freedoms 2 and 3) means you are free to redistribute copies, either with or without modifications, either gratis or charging a fee for distribution, to anyone anywhere. Being free to do these things means (among other things) that you do not have to ask or pay for permission to do so.
You should also have the freedom to make modifications and use them privately in your own work or play, without even mentioning that they exist. If you do publish your changes, you should not be required to notify anyone in particular, or in any particular way.
The freedom to run the program means the freedom for any kind of person or organization to use it on any kind of computer system, for any kind of overall job and purpose, without being required to communicate about it with the developer or any other specific entity. In this freedom, it is the user's purpose that matters, not the developer's purpose; you as a user are free to run the program for your purposes, and if you distribute it to someone else, she is then free to run it for her purposes, but you are not entitled to impose your purposes on her.
The freedom to run the program as you wish means that you are not forbidden or stopped from doing so. It has nothing to do with what functionality the program has, or whether it is useful for what you want to do.
The freedom to redistribute copies must include binary or executable forms of the program, as well as source code, for both modified and unmodified versions. (Distributing programs in runnable form is necessary for conveniently installable free operating systems.) It is OK if there is no way to produce a binary or executable form for a certain program (since some languages don't support that feature), but you must have the freedom to redistribute such forms should you find or develop a way to make them.
In order for freedoms 1 and 3 (the freedom to make changes and the freedom to publish the changed versions) to be meaningful, you must have access to the source code of the program. Therefore, accessibility of source code is a necessary condition for free software. Obfuscated “source code” is not real source code and does not count as source code.
Freedom 1 includes the freedom to use your changed version in place of the original. If the program is delivered in a product designed to run someone else's modified versions but refuse to run yours — a practice known as “tivoization” or “lockdown”, or (in its practitioners' perverse terminology) as “secure boot” — freedom 1 becomes an empty pretense rather than a practical reality. These binaries are not free software even if the source code they are compiled from is free.
One important way to modify a program is by merging in available free subroutines and modules. If the program's license says that you cannot merge in a suitably licensed existing module — for instance, if it requires you to be the copyright holder of any code you add — then the license is too restrictive to qualify as free.
Freedom 3 includes the freedom to release your modified versions as free software. A free license may also permit other ways of releasing them; in other words, it does not have to be a copyleft license. However, a license that requires modified versions to be nonfree does not qualify as a free license.
In order for these freedoms to be real, they must be permanent and irrevocable as long as you do nothing wrong; if the developer of the software has the power to revoke the license, or retroactively add restrictions to its terms, without your doing anything wrong to give cause, the software is not free.
However, certain kinds of rules about the manner of distributing free software are acceptable, when they don't conflict with the central freedoms. For example, copyleft (very simply stated) is the rule that when redistributing the program, you cannot add restrictions to deny other people the central freedoms. This rule does not conflict with the central freedoms; rather it protects them.
In the GNU project, we use copyleft to protect the four freedoms legally for everyone. We believe there are important reasons why it is better to use copyleft. However, noncopylefted free software is ethical too. See Categories of Free Software for a description of how “free software,” “copylefted software” and other categories of software relate to each other.
“Free software” does not mean “noncommercial”. A free program must be available for commercial use, commercial development, and commercial distribution. Commercial development of free software is no longer unusual; such free commercial software is very important. You may have paid money to get copies of free software, or you may have obtained copies at no charge. But regardless of how you got your copies, you always have the freedom to copy and change the software, even to sell copies.
Whether a change constitutes an improvement is a subjective matter. If your right to modify a program is limited, in substance, to changes that someone else considers an improvement, that program is not free.
However, rules about how to package a modified version are acceptable, if they don't substantively limit your freedom to release modified versions, or your freedom to make and use modified versions privately. Thus, it is acceptable for the license to require that you change the name of the modified version, remove a logo, or identify your modifications as yours. As long as these requirements are not so burdensome that they effectively hamper you from releasing your changes, they are acceptable; you're already making other changes to the program, so you won't have trouble making a few more.
Rules that “if you make your version available in this way, you must make it available in that way also” can be acceptable too, on the same condition. An example of such an acceptable rule is one saying that if you have distributed a modified version and a previous developer asks for a copy of it, you must send one. (Note that such a rule still leaves you the choice of whether to distribute your version at all.) Rules that require release of source code to the users for versions that you put into public use are also acceptable.
A special issue arises when a license requires changing the name by which the program will be invoked from other programs. That effectively hampers you from releasing your changed version so that it can replace the original when invoked by those other programs. This sort of requirement is acceptable only if there's a suitable aliasing facility that allows you to specify the original program's name as an alias for the modified version.
Sometimes government export control regulations and trade sanctions can constrain your freedom to distribute copies of programs internationally. Software developers do not have the power to eliminate or override these restrictions, but what they can and must do is refuse to impose them as conditions of use of the program. In this way, the restrictions will not affect activities and people outside the jurisdictions of these governments. Thus, free software licenses must not require obedience to any nontrivial export regulations as a condition of exercising any of the essential freedoms.
Merely mentioning the existence of export regulations, without making them a condition of the license itself, is acceptable since it does not restrict users. If an export regulation is actually trivial for free software, then requiring it as a condition is not an actual problem; however, it is a potential problem, since a later change in export law could make the requirement nontrivial and thus render the software nonfree.
A free license may not require compliance with the license of a nonfree program. Thus, for instance, if a license requires you to comply with the licenses of “all the programs you use”, in the case of a user that runs nonfree programs this would require compliance with the licenses of those nonfree programs; that makes the license nonfree.
It is acceptable for a free license to specify which jurisdiction's law applies, or where litigation must be done, or both.
Most free software licenses are based on copyright, and there are limits on what kinds of requirements can be imposed through copyright. If a copyright-based license respects freedom in the ways described above, it is unlikely to have some other sort of problem that we never anticipated (though this does happen occasionally). However, some free software licenses are based on contracts, and contracts can impose a much larger range of possible restrictions. That means there are many possible ways such a license could be unacceptably restrictive and nonfree.
We can't possibly list all the ways that might happen. If a contract-based license restricts the user in an unusual way that copyright-based licenses cannot, and which isn't mentioned here as legitimate, we will have to think about it, and we will probably conclude it is nonfree.
When talking about free software, it is best to avoid using terms like “give away” or “for free,” because those terms imply that the issue is about price, not freedom. Some common terms such as “piracy” embody opinions we hope you won't endorse. See Confusing Words and Phrases that are Worth Avoiding for a discussion of these terms. We also have a list of proper translations of “free software” into various languages.
Finally, note that criteria such as those stated in this free software definition require careful thought for their interpretation. To decide whether a specific software license qualifies as a free software license, we judge it based on these criteria to determine whether it fits their spirit as well as the precise words. If a license includes unconscionable restrictions, we reject it, even if we did not anticipate the issue in these criteria. Sometimes a license requirement raises an issue that calls for extensive thought, including discussions with a lawyer, before we can decide if the requirement is acceptable. When we reach a conclusion about a new issue, we often update these criteria to make it easier to see why certain licenses do or don't qualify.
If you are interested in whether a specific license qualifies as a free software license, see our list of licenses. If the license you are concerned with is not listed there, you can ask us about it by sending us email at <licensing@gnu.org>.
If you are contemplating writing a new license, please contact the Free Software Foundation first by writing to that address. The proliferation of different free software licenses means increased work for users in understanding the licenses; we may be able to help you find an existing free software license that meets your needs.
If that isn't possible, if you really need a new license, with our help you can ensure that the license really is a free software license and avoid various practical problems.

Beyond Software

Software manuals must be free, for the same reasons that software must be free, and because the manuals are in effect part of the software.
The same arguments also make sense for other kinds of works of practical use — that is to say, works that embody useful knowledge, such as educational works and reference works. Wikipedia is the best-known example.
Any kind of work can be free, and the definition of free software has been extended to a definition of free cultural works applicable to any kind of works.

Open Source?

Another group uses the term “open source” to mean something close (but not identical) to “free software”. We prefer the term “free software” because, once you have heard that it refers to freedom rather than price, it calls to mind freedom. The word “open” never refers to freedom.

History

From time to time we revise this Free Software Definition. Here is the list of substantive changes, along with links to show exactly what was changed.

• Version 1.141: Clarify which code needs to be free.
• Version 1.135: Say each time that freedom 0 is the freedom to run the program as you wish.
• Version 1.134: Freedom 0 is not a matter of the program's functionality.
• Version 1.131: A free license may not require compliance with a nonfree license of another program.
• Version 1.129: State explicitly that choice of law and choice of forum specifications are allowed. (This was always our policy.)
• Version 1.122: An export control requirement is a real problem if the requirement is nontrivial; otherwise it is only a potential problem.
• Version 1.118: Clarification: the issue is limits on your right to modify, not on what modifications you have made. And modifications are not limited to “improvements”
• Version 1.111: Clarify 1.77 by saying that only retroactive restrictions are unacceptable. The copyright holders can always grant additional permission for use of the work by releasing the work in another way in parallel.
• Version 1.105: Reflect, in the brief statement of freedom 1, the point (already stated in version 1.80) that it includes really using your modified version for your computing.
• Version 1.92: Clarify that obfuscated code does not qualify as source code.
• Version 1.90: Clarify that freedom 3 means the right to distribute copies of your own modified or improved version, not a right to participate in someone else's development project.
• Version 1.89: Freedom 3 includes the right to release modified versions as free software.
• Version 1.80: Freedom 1 must be practical, not just theoretical; i.e., no tivoization.
• Version 1.77: Clarify that all retroactive changes to the license are unacceptable, even if it's not described as a complete replacement.
• Version 1.74: Four clarifications of points not explicit enough, or stated in some places but not reflected everywhere:
  • "Improvements" does not mean the license can substantively limit what kinds of modified versions you can release. Freedom 3 includes distributing modified versions, not just changes.
  • The right to merge in existing modules refers to those that are suitably licensed.
  • Explicitly state the conclusion of the point about export controls.
  • Imposing a license change constitutes revoking the old license.
• Version 1.57: Add "Beyond Software" section.
• Version 1.46: Clarify whose purpose is significant in the freedom to run the program for any purpose.
• Version 1.41: Clarify wording about contract-based licenses.
• Version 1.40: Explain that a free license must allow to you use other available free software to create your modifications.
• Version 1.39: Note that it is acceptable for a license to require you to provide source for versions of the software you put into public use.
• Version 1.31: Note that it is acceptable for a license to require you to identify yourself as the author of modifications. Other minor clarifications throughout the text.
• Version 1.23: Address potential problems related to contract-based licenses.
• Version1.16: Explain why distribution of binaries is important.
• Version1.11: Note that a free license may require you to send a copy of versions you distribute to the author.

There are gaps in the version numbers shown above because there are other changes in this page that do not affect the definition or its interpretations. For instance, the list does not include changes in asides, formatting, spelling, punctuation, or other parts of the page. You can review the complete list of changes to the page through the cvsweb interface.

How to use GNU licenses for your own software

How to use GNU licenses for your own software

This is a brief explanation of how to place a program under the GNU General Public License, Lesser General Public License, or Affero General Public License. For the GNU Free Documentation License, we have a separate page.

If you are looking for more detailed information, consider perusing our list of frequently asked questions about our licenses.

If you are considering using the GNU Lesser General Public License, please read the article “Why you shouldn't use the LGPL for your next library” first. The article explains why it may be better to use the ordinary GPL instead, and how we would make the decision.
Whichever license you plan to use, the process involves adding two elements to each source file of your program: a copyright notice (such as “Copyright 1999 Terry Jones”), and a statement of copying permission, saying that the program is distributed under the terms of the GNU General Public License (or the Lesser GPL).
The copyright notice should include the year in which you finished preparing the release (so if you finished it in 1998 but didn't post it until 1999, use 1998). You should add the proper year for each release; for example, “Copyright 1998, 1999 Terry Jones” if some versions were finished in 1998 and some were finished in 1999. If several people helped write the code, use all their names.
For software with several releases over multiple years, it's okay to use a range (“2008-2010”) instead of listing individual years (“2008, 2009, 2010”) if and only if every year in the range, inclusive, really is a “copyrightable” year that would be listed individually; and you make an explicit statement in your documentation about this usage.
Always use the English word “Copyright”; by international convention, this is used worldwide, even for material in other languages. The copyright symbol “©” can be included if you wish (and your character set supports it), but it's not necessary. There is no legal significance to using the three-character sequence “(C)”, although it does no harm.
You should also include a copy of the license itself somewhere in the distribution of your program. All programs, whether they are released under the GPL or LGPL, should include the text version of the GPL. In GNU programs the license is usually in a file called COPYING.

If you are releasing your program under the LGPL, you should also include the text version of the LGPL, usually in a file called COPYING.LESSER. Please note that, since the LGPL is a set of additional permissions on top of the GPL, it's important to include both licenses so users have all the materials they need to understand their rights.

If you are releasing your program under the GNU AGPL, you only need to include the text version of the GNU AGPL.
If you have copied code from other programs covered by the same license, copy their copyright notices too. Put all the copyright notices together, right near the top of each file.
It is very important for practical reasons to include contact information for how to reach you, perhaps in the README file, but this has nothing to do with the legal issues of applying the license.
The copying permission statement should come right after the copyright notices. For a one-file program, the statement (for the GPL) should look like this:

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

For programs that are more than one file, it is better to replace “this program” with the name of the program, and begin the statement with a line saying “This file is part of NAME”. For instance,

    This file is part of Foobar.

    Foobar is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Foobar is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This statement should go near the beginning of every source file, close to the copyright notices. When using the Lesser GPL, insert the word “Lesser” before “General” in all three places. When using the GNU AGPL, insert the word “Affero” before “General” in all three places.
For interactive programs, it is usually a good idea to make the program print out a brief notice about copyright and copying permission when it starts up. See the end of the GNU GPL for more information about this.
If you are releasing your program under the GNU AGPL, and it can interact with users over a network, the program should offer its source to those users in some way. For example, if your program is a web application, its interface could display a “Source” link that leads users to an archive of the code. The GNU AGPL is flexible enough that you can choose a method that's suitable for your specific program—see section 13 for details.
There is no legal requirement to register your copyright with anyone; simply distributing the program makes it copyrighted. However, it is a very good idea to register the copyright with the US Registry of Copyrights, because that puts you in a stronger position against anyone who violates the license in the US. Most other countries have no system of copyright registration.
It's wise to ask your employer or school, if any, to sign a copyright disclaimer for the work, so they cannot claim to hold it later. Below is a sample copyright disclaimer; just alter the names and program description as appropriate:

Yoyodyne, Inc., hereby disclaims all copyright interest in the program “Gnomovision” (which makes passes at compilers) written by James Hacker.
<signature of Moe Ghoul>, 1 April 1989
Moe Ghoul, President of Vice

We would like to list all free software programs in the Free Software Directory, including all programs licensed under the GPL (any version). Please see the Directory web page for information and an online submission form.
It is also possible to make your program a GNU package, a part of the GNU Project. (That's if we like the program we have to look at it first, and decide.) If you might be interested in joining up with the GNU Project in this way, please see our GNU software evaluation page for more information and a short questionnaire.

But you are welcome to use any of our licenses even if your program is not a GNU package; indeed, we hope you will. They're available to everyone. If you'd like to advertise your use of a particular license, feel free to use one of our logos.

GNU GENERAL PUBLIC LICENSE

Preamble

The GNU General Public License is a free, copyleft license for software and other kinds of works.
The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.
To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.
For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions.
Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.
Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.
The precise terms and conditions for copying, distribution and modification follow.

TERMS AND CONDITIONS

0. Definitions.

“This License” refers to version 3 of the GNU General Public License.
“Copyright” also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.
“The Program” refers to any copyrightable work licensed under this License. Each licensee is addressed as “you”. “Licensees” and “recipients” may be individuals or organizations.
To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a “modified version” of the earlier work or a work “based on” the earlier work.
A “covered work” means either the unmodified Program or a work based on the Program.
To “propagate” a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well.
To “convey” a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying.
An interactive user interface displays “Appropriate Legal Notices” to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion.

1. Source Code.

The “source code” for a work means the preferred form of the work for making modifications to it. “Object code” means any non-source form of a work.
A “Standard Interface” means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language.
The “System Libraries” of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A “Major Component”, in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it.
The “Corresponding Source” for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work.
The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source.
The Corresponding Source for a work in source code form is that same work.

2. Basic Permissions.

All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work. This License acknowledges your rights of fair use or other equivalent, as provided by copyright law.
You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you.
Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary.

3. Protecting Users' Legal Rights From Anti-Circumvention Law.

No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures.
When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures.

4. Conveying Verbatim Copies.

You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program.
You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee.

5. Conveying Modified Source Versions.

You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions:

• a) The work must carry prominent notices stating that you modified it, and giving a relevant date.
• b) The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to “keep intact all notices”.
• c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it.
• d) If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so.

A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an “aggregate” if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate.

6. Conveying Non-Source Forms.

You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways:

• a) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange.
• b) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge.
• c) Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b.
• d) Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements.
• e) Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d.

A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work.
A “User Product” is either (1) a “consumer product”, which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, “normally used” refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product.
“Installation Information” for a User Product means any methods, procedures, authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source. The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made.
If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM).
The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network.
Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying.

7. Additional Terms.

“Additional permissions” are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions.
When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission.
Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms:

• a) Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or
• b) Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or
• c) Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or
• d) Limiting the use for publicity purposes of names of licensors or authors of the material; or
• e) Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or
• f) Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors.

All other non-permissive additional terms are considered “further restrictions” within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying.
If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms.
Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way.

8. Termination.

You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11).
However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.
Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10.

9. Acceptance Not Required for Having Copies.

You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so.

10. Automatic Licensing of Downstream Recipients.

Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License.
An “entity transaction” is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts.
You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it.

11. Patents.

A “contributor” is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's “contributor version”.
A contributor's “essential patent claims” are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, “control” includes the right to grant patent sublicenses in a manner consistent with the requirements of this License.
Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.
In the following three paragraphs, a “patent license” is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party.
If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. “Knowingly relying” means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid.
If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it.
A patent license is “discriminatory” if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007.
Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.

12. No Surrender of Others' Freedom.

If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.

13. Use with the GNU Affero General Public License.

Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.

14. Revised Versions of this License.

The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.
Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.
If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program.
Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.

15. Disclaimer of Warranty.

THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

16. Limitation of Liability.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

17. Interpretation of Sections 15 and 16.

If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.
END OF TERMS AND CONDITIONS

How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.
If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.
You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see <http://www.gnu.org/licenses/>.
The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read <http://www.gnu.org/philosophy/why-not-lgpl.html>.