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Linux license

The Open Source Definition (Version 1.0)

Open source doesn't just mean access to the source code. The distribution terms of an open-source program must comply with the following criteria:

Note that the Open Source Definition is not itself a software license. It is a specification of what is permissible in a software license for that software to be referred to as Open Source. The Open Source Definition was not intended to be a legal document. The inclusion of the Open Source Definition in software licenses, such as a proposed license of the Linux Documentation Project, has tempted me to write a more rigorous version that would be appropriate for that use.

To be Open Source, all of the terms below must be applied together, and in all cases. For example, they must be applied to derived versions of a program as well as the original program. It's not sufficient to apply some and not others, and it's not sufficient for the terms to only apply some of the time. After working through some particularly naive interpretations of the Open Source Definition, I feel tempted to add: this means you!

Free Redistribution The license may not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license may not require a royalty or other fee for such sale. This means that you can make any number of copies of the software, and sell or give them away, and you don't have to pay anyone for that privilege. The "aggregate software distribution containing programs from several different sources" was intended to fit a loophole in the Artistic License,a rather sloppy license in my opinion, originally designed for Perl. Today, almost all programs that use the Artistic License are also available under the GPL. That provision is thus no longer necessary, and may be removed from a future version of the Open Source Definition. Source Code The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of downloading the source code, without charge, via the Internet. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed. Source code is a necessary preliminary for the repair or modification of a program. The intent here is for source code to be distributed with the initial work, and all derived works. Derived Works The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.Software has little use if you can't maintain it ( fix bugs, port to new systems, make improvements), and modification is necessary for maintenance. The intent here is for modification of any sort to be allowed. It must be allowed for a modified work to be distributed under the same license terms as the original work. However, it is not required that any producer of a derived work must use the same license terms, only that the option to do so be open to them.

Various licenses speak differently on this subject--the BSD license allows you to take modifications private, while the GPL does not. A concern among some software authors is that this provision could allow unscrupulous people to modify their software in ways that would embarrass the original author. They fear someone deliberately making the software perform incorrectly in a way that would make it look as if the author was a poor programmer. Others are concerned that software could be modified for criminal use, by the addition of Trojan horse functions or locally-banned technologies such as cryptography. All of these actions, however, are covered by criminal law. A common misunderstanding about software licenses is that they must specify everything, including things like "don't use this software to commit a crime." However, no license has any valid existence outside of the body of civil and criminal law.Considering a license as something apart from the body of applicable law is as silly as considering an English-language document as being apart from the dictionary, in which case none of the words would have any defined meaning.

Integrity of the Author's Source Code The license may restrict source code from being distributed in modified form only if the license allows the distribution of "patch files" with the source code for the purpose of modifying the program at build time. Some authors were afraid that others would distribute source code with modifications that would be perceived as the work of the original author,and would reflect poorly on that author. This gives them a way to enforce a separation between modifications and their own work without prohibiting modifications. Some consider it un-aesthetic that modifications might have to be distributed in a separate "patch" file from the source code, even though Linux distributions like Debian and Red Hat use this procedure for all of the modifications they make to the programs they distribute. There are programs that automatically merge patches into the main source, and one can have these programs run automatically when extracting a source package. Thus, this provision should cause little or no hardship.

Note also that this provision says that in the case of patch files, the modification takes place at build-time. This loophole is employed in the Qt Public License to mandate a different, though less restrictive, license for the patch files, in contradiction of Section 3 of the Open Source Definition. There is a proposal to clean up this loophole in the definition while keeping Qt within Open Source. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software. This means that Netscape, for example, can insist that only they can name a version of the program Netscape Navigator(tm) while all free versions of the program must be called Mozilla or something else. No Discrimination Against Persons or Groups The license must not discriminate against any person or group of persons. A license provided by the Regents of the University of California, Berkeley, prohibited an electronic design program from being used by the police of South Africa. While this was a laudable sentiment in the time of apartheid, it makes little sense today. Some people are still stuck with software that they acquired under that license, and their derived versions must carry the same restriction. Open Source licenses may not contain such provisions, no matter how laudable their intent. No Discrimination Against Fields of Endeavor The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research. Your software must be equally usable in an abortion clinic, or by an anti-abortion organization. These political arguments belong on the floor of Congress, not in software licenses. Some people find this lack of discrimination extremely offensive! Distribution of License The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties. The license must be automatic, no signature required. Unfortunately, there has not been a good court test in the U.S. of the power of a no-signature-required license when it is passed from a second party to a third. However, this argument considers the license in the body of contract law, while some argue that it should be considered as copyright law, where there is more precedent for no-signature licenses. A good court test will no doubt happen in the next few years, given the popularity of this sort of license and the booming nature of Open Source. License Must Not Be Specific to a Product The rights attached to the program must not depend on the program's being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program's license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution. This means you can't restrict a product that is identified as Open Source to be free only if you use it with a particular brand of Linux distribution, etc. It must remain free if you separate it from the software distribution it came with. License Must Not Contaminate Other Software The license must not place restrictions on other software that is distributed along with the licensed software. For example, the licenses must not insist that all other programs distributed on the same medium must be open-source software. A version of GhostScript (a PostScript-rendering program) requires that the media on which it is distributed contain only free software programs. This isn't permissible for Open Source licenses. Fortunately, the GhostScript author distributes another (somewhat older) version of the program with a true Open Source license. Note that there is a difference between derivation and aggregation. Derivation is when a program actually incorporates part of another program into itself. Aggregation is when you include two programs on the same CD-ROM. This section of the Open Source Definition is concerned with aggregation , not derivation. Section 4 is concerned with derivation. Example Licenses The GNU GPL, BSD, X Consortium, and Artistic licenses are examples of licenses that we consider conformant to the Open Source Definition. So is the MPL. This would get us in trouble if any of these licenses are ever changed to be non-Open-Source--we'd have to issue a revision of the Open Source Definition immediately. It really belongs in explanatory text, not in the Open Source Definition itself.

Analysis of Licenses and Their Open Source Compliance

To understand the Open Source Definition, we need to look at some common licensing practices as they relate to Open Source.

Public Domain

A common misconception is that much free software is public-domain. This happens simply because the idea of free software or Open Source is confusing to many people, and they mistakenly describe these programs as public-domain because that's the closest concept that they understand. The programs, however, are clearly copyrighted and covered by a license, just a license that gives people more rights than they are used to. A public-domain program is one upon which the author has deliberately surrendered his copyright rights. It can't really be said to come with a license; it's your personal property to use as you see fit. Because you can treat it as your personal property, you can do what you want with a public-domain program. You can even re-license a public-domain program, removing that version from the public domain, or you can remove the author's name and treat it as your own work.

If you are doing a lot of work on a public-domain program, consider applying your own copyright to the program and re-licensing it. For example, if you don't want a third party to make their own modifications that they then keep private, apply the GPL or a similar license to your version of the program. The version that you started with will still be in the public domain, but your version will be under a license that others must heed if they use it or derive from it. You can easily take a public-domain program private, by declaring a copyright and applying your own license to it or simply declaring "All Rights Reserved."

Free Software Licenses in General

If you have a free software collection like a Linux disk, you may believe the programs on that disk are your property. That's not entirely true. Copyrighted programs are the property of the copyright holder, even when they have an Open Source license like the GPL. The program's license grants you some rights, and you have other rights under the definition of fair use in copyright law. It's important to note that an author does not have to issue a program with just one license. You can GPL a program, and also sell a version of the same program with a commercial, non-Open-Source license. This exact strategy is used by many people who want to make a program Open Source and still make some money from it. Those who do not want an Open Source license may pay for the privilege, providing a revenue stream for the author.

All of the licenses we will examine have a common feature: they each disclaim all warranties. The intent is to protect the software owner from any liability connected with the program. Since the program is often being given away at no cost, this is a reasonable requirement--the author doesn't have a sufficient revenue stream from the program to fund liability insurance and legal fees. If free-software authors lose the right to disclaim all warranties and find themselves getting sued over the performance of the programs that they've written, they'll stop contributing free software to the world. It's to our advantage as users to help the author protect this right.

The GNU General Public License

Please see Appendix B for the full text of the GPL. The GPL is a political manifesto as well as a software license, and much of its text is concerned with explaining the rationale behind the license. This political dialogue has put some people off, and thus provided some of the reason that people have written other free software licenses. However, the GPL was assembled with the assistance of law professors, and is much better written than most of its ilk. I'd strongly urge that you use the GPL, or its library variant the LGPL, if you can. If you choose another license, or write your own, be sure about your reasons. People who write their own licenses should consider that this is not a step to be taken lightly. The unexpected complications of an ill-considered license can create a decades-long burden for software users. The text of the GPL is not itself under the GPL. Its license is simple: Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. An important point here is that the text of the licenses of Open Source software are generally not themselves Open Source. Obviously, a license would offer no protection if anyone could change it.

The provisions of the GPL satisfy the Open Source Definition. The GPL does not require any of the provisions permitted by paragraph 4 of the Open Source Definition, Integrity of the Author's Source Code. The GPL does not allow you to take modifications private. Your modifications must be distributed under the GPL. Thus, the author of a GPL-ed program is likely to receive improvements from others, including commercial companies who modify his software for their own purposes. The GPL doesn't allow the incorporation of a GPL-ed program into a proprietary program. The GPL's definition of a proprietary program is any program with a license that doesn't give you as many rights as the GPL. There are a few loopholes in the GPL that allow it to be used in programs that are not entirely Open Source. Software libraries that are normally distributed with the compiler or operating system you are using may be linked with GPL-ed software; the result is a partially-free program. The copyright holder (generally the author of the program) is the person who places the GPL on the program and has the right to violate his own license. This was used by the KDE authors to distribute their programs with Qt before Troll Tech placed an Open Source license on Qt. However, this right does not extend to any third parties who redistribute the program--they must follow all of the terms of the license, even the ones that the copyright holder violates, and thus it's problematical to redistribute a GPL-ed program containing Qt. The KDE developers appear to be addressing this problem by applying the LGPL, rather than the GPL, to their software. The political rhetoric in the GPL puts some people off. Some of them have chosen a less appropriate license for their software simply because they eschew Richard Stallman's ideas and don't want to see them repeated in their own software packages.

The GNU Library General Public License

The LGPL is a derivative of the GPL that was designed for software libraries. Unlike the GPL, a LGPL-ed program can be incorporated into a proprietary program. The C-language library provided with Linux systems is an example of LGPL-ed software--it can be used to build proprietary programs, otherwise Linux would only be useful for free software authors. An instance of an LGPL-ed program can be converted into a GPL-ed one at any time. Once that happens, you can't convert that instance, or anything derived from it, back into an LGPL-ed program. The rest of the provisions of the LGPL are similar to those in the GPL--in fact, it includes the GPL by reference.

The X, BSD, and Apache Licenses

The X license and its relatives the BSD and Apache licenses are very different from the GPL and LGPL. These licenses let you do nearly anything with the software licensed under them. This is because the software that the X and BSD licenses originally covered was funded by monetary grants of the U.S. Government. Since the U.S. citizens had already paid for the software with their taxes, they were granted permission to make use of that software as they pleased. The most important permission, and one missing from the GPL, is that you can take X-licensed modifications private. In other words, you can get the source code for a X-licensed program, modify it, and then sell binary versions of the program without distributing the source code of your modifications, and without applying the X license to those modifications. This is still Open Source, however, as the Open Source Definition does not require that modifications always carry the original license.

Many other developers have adopted the X license and its variants, including the BSD (Berkeley System Distribution) and the Apache web server project. An annoying feature of the BSD license is a provision that requires you to mention (generally in a footnote) that the software was developed at the University of California any time you mention a feature of a BSD-licensed program in advertising. Keeping track of which software is BSD-licensed in something huge like a Linux distribution, and then remembering to mention the University whenever any of those programs are mentioned in advertising,is somewhat of a headache for business people. At this writing, the Debian GNU/Linux distribution contains over 2,500 software packages, and if even a fraction of them were BSD-licensed, advertising for a Linux system like Debian might contain many pages of footnotes! However, the X Consortium license does not have that advertising provision. If you are considering using a BSD-style license, use the X license instead.

The Artistic License

Although this license was originally developed for Perl, it's since been used for other software. It is, in my opinion, a sloppily-worded license, in that it makes requirements and then gives you loopholes that make it easy to bypass the requirements. Perhaps that's why almost all Artistic-license software is now dual-licensed, offering the choice of the Artistic License or the GPL. Section 5 of the Artistic License prohibits sale of the software, yet allows an aggregate software distribution of more than one program to be sold. So, if you bundle an Artistic-licensed program with a five-line hello-world.c, you can sell the bundle. This feature of the Artistic License was the sole cause of the "aggregate" loophole in paragraph 1 of the Open Source Definition. As use of the Artistic License wanes, we are considering removing the loophole. That would make the Artistic a non-Open-Source license. This isn't a step we would take lightly, and there will probably be more than a year of consideration and debate before it happens. The Artistic License requires you to make modifications free, but then gives you a loophole (in Section 7) that allows you to take modifications private or even place parts of the Artistic-licensed program in the public domain!

The Netscape Public License and the Mozilla Public License

NPL was developed by Netscape when they made their product Netscape Navigator Open Source. Actually, the Open-Source version is called Mozilla; Netscape reserves the trademark Navigator for their own product. Eric Raymond and I acted as unpaid consultants during the development of this license. I tried, unsuccessfully, to persuade Netscape to use the GPL, and when they declined, I helped them compose a license that would comply with the Open Source Definition. An important feature of the NPL is that it contains special privileges that apply to Netscape and nobody else. It gives Netscape the privilege of re-licensing modifications that you've made to their software. They can take those modifications private, improve them, and refuse to give you the result. This provision was necessary because when Netscape decided to go Open Source, it had contracts with other companies that committed it to provide Navigator to them under a non-Open-Source license. Netscape created the MPL, or Mozilla Public License, to address this concern. The MPL is much like the NPL, but does not contain the clause that allows Netscape to re-license your modifications. The NPL and MPL allow you to take modifications private. Many companies have adopted a variation of the MPL for their own programs. This is unfortunate, because the NPL was designed for the specific business situation that Netscape was in at the time it was written, and is not necessarily appropriate for others to use. It should remain the license of Netscape and Mozilla, and others should use the GPL or the or X licenses.

Choosing a License

Do not write a new license if it is possible to use one of the ones listed here. The propagation of many different and incompatible licenses works to the detriment of Open Source software because fragments of one program cannot be used in another program with an incompatible license. Steer clear of the Artistic License unless you are willing to study it carefully and edit out its loopholes. Then, make a few decisions:

Do you want people to be able to take modifications private or not? If you want to get the source code for modifications back from the people who make them, apply a license that mandates this. The GPL and LGPL would be good choices. If you don't mind people taking modifications private, use the X or Apache license. Do you want to allow someone to merge your program with their own proprietary software? If so, use the LGPL, which explicitly allows this without allowing people to make modifications to your own code private, or use the X or Apache licenses, which do allow modifications to be kept private. Do you want some people to be able to buy commercial-licensed versions of your program that are not Open Source? If so, dual-license your software. I recommend the GPL as the Open Source license; you can find a commercial license appropriate for you to use in books like Copyright Your Software from Nolo Press. Do you want everyone who uses your program to pay for the privilege? If so, perhaps Open Source isn't for you. If you're satisfied with having only some people pay you,you can work that and keep your program Open Source. Most of the Open Source authors consider their programs to be contributions to the public good, and don't care if they are paid at all.

The Future

As this essay went to press, IBM joined the Open Source world, and the venture capital community is discovering Open Source. Intel and Netscape have invested in Red Hat, a Linux distributor. VA Research, an integrator of Linux server and workstation hardware, has announced an outside investor. Sendmail Inc., created to commercialize the ubiquitous Sendmail e mail delivery program, has announced six million dollars in funding. IBM's Postfix secure mailer has an Open Source license, and another IBM product, the Jikes Java compiler, has a license that, at this writing, tries but doesn't quite meet the intent of the Open Source Definition. IBM appears to be willing to modify the Jikes license to be fully Open Source, and is collecting comments from the community as I write this. Two internal Microsoft memos, referred to as the Halloween Documents, were leaked to the online public. These memos clearly document that Microsoft is threatened by Open Source and Linux, and that MS will launch an offensive against them to protect its markets. Obviously, we are in for some interesting times. I think we'll see Microsoft use two main strategies: copyrighted interfaces and patents. Microsoft will extend networking protocols, including Microsoft-specific features in them that will not be made available to free software. They, and other companies, will aggressively research new directions in computer science and will patent whatever they can before we can first use those techniques in free software, and then they'll lock us out with patent royalty fees. I've written an essay for the webzine Linux World on how to fight Open Source's enemies on the patent front. The good news is that Microsoft is scared! In the second Halloween document, a Microsoft staffer writes about the exhilarating feeling that he could easily change part of the Linux system to do exactly what he wanted, and that it was so much easier to do this on Linux than it was for a Microsoft employee to change NT! Efforts to hurt us from inside are the most dangerous. I think we'll also see more attempts to dilute the definition of Open Source to include partially-free products, as we saw with the Qt library in KDE before Troll Tech saw the light and released an Open Source license. Microsoft and others could hurt us by releasing a lot of software that's just free enough to attract users without having the full freedoms of Open Source. It's conceivable that they could kill off development of some categories of Open Source software by releasing a "good enough," "almost-free-enough" solution. However,the strong reaction against the KDE project before the Qt library went fully Open Source bodes poorly for similar efforts by MS and its ilk.

We've escaped Trojan horses so far. Suppose that someone who doesn't like us contributes software that contains Trojan horse, a hidden way to defeat the security of a Linux system. Suppose, then, that this person waits for the Trojan-horse software to be widely distributed, and then publicizes its vulnerability to security exploits. The public will then have seen that our Open Source system may leave us more vulnerable to this sort of exploit than the closed system of Microsoft, and this may reduce the public's trust in Open Source software. We can argue that Microsoft has its share of security bugs even if they don't allow outsiders to insert them, and that the disclosed source-code model of Open Source makes these bugs easier to find. Any bug like this that comes up on Linux will be fixed the day after it's announced, while a similar bug in Windows might go undetected or unrepaired for years. But we still need to beef up our defense against Trojan horses. Having good identification of the people who submit software and modifications is our best defense, as it allows us to use criminal law against the perpetrators of Trojan horses. While I was manager of the Debian GNU/Linux distribution, we instituted a system for all of our software maintainers to be reliably identified, and for them to participate in a public-key cryptography network that would allow us to verify whom our software came from. This sort of system has to be expanded to include all Open Source developers.

We have tremendous improvements to make before Linux is ready for the average person to use. The graphical user interface is an obvious deficit, and GNOME projects are addressing this. System administration is the next frontier: while linuxconf partially addresses this issue, if falls far short of being a comprehensive system-administration tool for the naive user. If Caldera's COAS system is successful, it could become the basis of a full solution to the system administration problem. However, Caldera has had trouble keeping sufficient resources allocated to COAS to finish its participants have dropped off the bandwagon due to the lack of progress. The plethora of Linux distributions appear to be going through a shake-out, with Red Hat as the perceived winner and Caldera coming in second. Red Hat has shown a solid commitment to the concept of Open Source so far, but a new president and rumors of an Initial Public Offering (IPO) could mean a weakening of this commitment, especially if competitors like Caldera, who are not nearly as concerned about Open Source, make inroads into Red Hat's markets. If the commitment of commercial Linux distributions to Open Source became a problem, that would probably spawn an effort to replace them with pure Open Source efforts similar to Debian GNU/Linux, but ones more directed to the commercial market than Debian has been.

Despite these challenges, I predict that Open Source will win. Linux has become the testbed of computer science students, and they will carry those systems with them into the workplace as they graduate. Research laboratories have adopted the Open Source model because the sharing of information is essential to the scientific method, and Open Source allows software to be shared easily. Businesses are adopting the Open Source model because it allows groups of companies to collaborate in solving a problem without the threat of an anti-trust lawsuit, and because of the leverage they gain when the computer-programming public contributes free improvements to their software. Some large corporations have adopted Open Source as a strategy to combat Microsoft and to assure that another Microsoft does not come to dominate the computer industry. But the most reliable indication of the future of Open Source is its past: in just a few years, we have gone from nothing to a robust body of software that solves many different problems and is reaching the million-user count. There's no reason for us to slow down now.

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If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), 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 distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program.

If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances. It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License. If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. The Free Software Foundation may publish revised and/or new versions of the 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 a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation.

If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally.

NO WARRANTY BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, 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. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE 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. 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 convey 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 an idea of what it does. Copyright (C) 19yy 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 2 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, write to the Free Software Foundation, Inc., 59 Temple Place--Suite 330, Boston, MA 02111-1307, USA. Also add information on how to contact you by electronic and paper mail.If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) 19yy name of author Gnomovision 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, the commands you use may be called something other than "show w" and "show c"; they could even be mouse-clicks or menu items--whatever suits your program.You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker.Signature of Ty Coon, 1 April 1989 Ty Coon, President of Vice This 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 Library General Public License instead of this License. FSF & GNU inquiries & questions to gnu@gnu.org. Other ways to contact the FSF.these web pages to webmasters@www.gnu.org, send other questions to gnu@gnu.org. Copyright notice above. Free Software Foundation, Inc., 59 Temple Place--Suite 330, Boston, MA 02111, USA Updated: 16 Feb 1998 tower With the Linux kernel, Linus Torvalds includes the following preamble to the GPL: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls--this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work." Also note that the GPL below is copyrighted by the Free Software Foundation,but the instance of code that it refers to (the Linux kernel) is copyrighted by me and others who actually wrote it.

Linus Torvalds

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