Free software is software which grants recipients the freedom to modify and redistribute the software. This would normally be prohibited by Copyright law, so with free software, the copyright holder must give recipients the explicit permission to do these things. This grant of rights is called a license, and if the above noted freedoms are included in the grant, the license is a free software license. This article is about free software as defined by the sociopolitical free software movement; for information on software distributed without charge, see freeware. ... Computer software (or simply software) refers to one or more computer programs and data held in the storage of a computer for some purpose. ... Mohandas K. Gandhi - Freedom can be achieved through inner sovereignty. ... Like John says copyright law in the UK is u make something and its copyrighted but in america u must make a patent haaaa ...

Put another way, a free software license is a license which grants permissions to the recipient to remove any ownership issues which would otherwise prevent the software from being free software. It has been suggested that Licensing (strategic alliance) be merged into this article or section. ... This article is about free software as defined by the sociopolitical free software movement; for information on software distributed without charge, see freeware. ...

FSF-approved free software licenses

Free Software Foundation, the group that maintains The Free Software Definition, maintains a list of free software licenses. The list distinguishes between free software licenses that are compatible or incompatible with the FSF license of choice, the GNU General Public License, which is a copyleft license. The list also contains licenses which the FSF considers non-free for various reasons. Note that the open source license list differs slightly, but in almost all cases the definitions apply to the same licenses. The Free Software Foundation logo The Free Software Foundation (FSF) is a non-profit organization founded in October 1985 by Richard Stallman to support the free software movement (free as in freedom), and in particular the GNU project. ... This article is about free software as defined by the Free Software Foundation. ... The GNU logo The GNU General Public License (GNU GPL or simply GPL) is a widely used free software license, originally written by Richard Stallman for the GNU project. ... The reversed c is the copyleft symbol. ... Free Software Foundation (FSF) is a non-profit organisation founded in 1985 by Richard Stallman to support the free software movement (free as in freedom), and in particular the GNU project. ... An open-source license is a copyright license for computer software that makes the source code available under terms that allow for modification and royalty-free redistribution. ...

The Academic Free License is an open source / free software license written in 2002 by Lawrence E. Rosen, general counsel of the Open Source Initiative. ... // Affero General Public License The Affero General Public License (or AGPL) is a free software license derived from the General Public License with an addition section to cover use over a computer network. ... The Apache License (Apache Software License previous to version 2. ... The Apple Public Source License is the open source license under which Apple Computers Darwin Project was released. ... The Artistic License is a software license used for certain free software packages, most notably the standard Perl implementation, most of CPAN modules and Parrot, which are dual-licensed under the Artistic License and the GNU General Public License (GPL). ... Sleepycat Public License is an OSI-approved open-source license used by Sleepycat Software for their products Berkeley DB, Berkeley DB Java Edition and Berkeley DB XML. According to Free Software Foundation, it qualifies as a free software license, and is compatible with the GNU General Public License. ... CeCILL (from CEA CNRS INRIA Logiciel Libre) is a Free Software license adapted to both International and French legal matters, in the spirit of and retaining compatibility with the GNU General Public License. ... Common Development and Distribution License (CDDL) is an open source and Free software license, produced by Sun Microsystems, based on the Mozilla Public License (MPL), version 1. ... The CPL (Common Public License) is a free software / open-source software license published by IBM. Its license terms have been approved by the Open Source Initiative and Free Software Foundation. ... License in use by the Cryptix project, well known for their Java Cryptography Extension. ... The Eclipse Public License (EPL) is a license for free software. ... The GNU logo The GNU General Public License (GNU GPL or simply GPL) is a widely used free software license, originally written by Richard Stallman for the GNU project. ... GNU logo The GNU Lesser General Public License (formerly the GNU Library General Public License) is a free software license published by the Free Software Foundation. ... The IBM Public License is a free software / open-source software license used by IBM. It is ratified by the Open Source Initiative and Free Software Foundation (FSF). ... The Intel Open Source license is identical to the BSD license with the following section added EXPORT LAWS: THIS LICENSE ADDS NO RESTRICTIONS TO THE EXPORT LAWS OF YOUR JURISDICTION. It is licensees responsibility to comply with any export regulations applicable in licensees jurisdiction. ... The LaTeX Project Public License is a software license originally written for the LaTeX system. ... The GNU logo The GNAT Modified General Public License (short: Modified GPL, GMGPL) is a version of the GNU General Public License specifically modified for the generic feature found in the Ada programming language. ... The zlib/libpng license is a software license that applies to zlib, libpng and other non-related software packages. ... The MIT License, also called the X License or the X11 License, originated at the Massachusetts Institute of Technology, is a license for the use of certain types of computer software. ... The BSD license is an acronym for the Berkeley Software Distribution license agreement, and is one of the most widely used licenses for free software (a subset of open source software). ... FreeBSD is a Unix-like free operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD) branch through the 386BSD and 4. ... OpenBSD is a freely available Unix-like computer operating system descended from Berkeley Software Distribution (BSD), a Unix derivative developed at the University of California, Berkeley. ... In computing, the Mozilla Public License is an open source and free software license. ... The Netscape Public License (NPL) is a free software license, the license under which Netscape Communications Corporation originally released Mozilla. ... The Open Software License (OSL) is a software licence created by Lawrence Rosen. ... The OpenSSL exception is a clause added to the GNU General Public License (GPL) by free software developers who want to use OpenSSL with their software. ... The BSD license is a permissive license and is one of the most widely used licenses for free software. ... NetBSD is a freely redistributable, open source version of the Unix-like BSD computer operating system. ... For the PHP Cold War history project, see Parallel History Project. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... The Python Software Foundation License is a free software license which is compatible with the GNU General Public License (GPL). ... The Q Public License (QPL) is a non-copyleft free software license created by Trolltech for its free edition of the Qt toolkit. ... The Sun Industry Standards Source License (SISSL) is a now-retired free and open source license, recognized as such by the Free Software Foundation and the Open Source Initiative. ... The Sun Public License (SPL) is a software license that applies to some open-source software released by Sun Microsystems (such as NetBeans). ... Ruby is a reflective, object-oriented programming language. ... W3C Software Notice and License is an Open Source licence used by software released by W3C, like Amaya. ... The MIT License, originated at the Massachusetts Institute of Technology, is a license for the use of certain types of computer software. ... The MIT License, also called the X License or the X11 License, originated at the Massachusetts Institute of Technology, is a license for the use of certain types of computer software. ... Zope Public License is a free software license, used primarily for the Zope application server software. ...

Freedom preserving restrictions

To preserve the freedoms to use, study, modify, and redistribute the software, most free software licences include restrictions and requirements which apply to distributors. There is constant debate within the free software community about where to draw the line between restrictions that preserve freedom and restrictions that reduce freedom. // The free software community is also called the open source community or the Linux community. ...

Copyleft

Main article: copyleft

Since the mid 80s, free software licences written by Richard Stallman pioneered a concept known as copyleft. Copyleft provisions say that modified versions of the software must be distributed under the same terms under which the unmodified software was received. Thus, additions and improvements to copylefted free software must also be distributed as free software. This is sometimes referred to as "share and share alike", or "quid pro quo". The reversed c is the copyleft symbol. ...

Patent retaliation

Most newly written free software licences from the late 90s onward include some form of patent retaliation. This means that a persons' rights under the licence (such as to redistribute) are terminated under certain conditions. For example, the Apple Public Source Licence terminates the users' rights if the user sues Apple for patent litigation.

DRM and Tivoisation

As of late 2006, no free software licences contain explicit wordings to prohibit additional restrictions being enforced by Digital Restrictions Management (DRM). Current discussion drafts of version 3 of the GNU General Public License include wordings to prevent "tivoisation". Digital Rights Management or Digital Restrictions Management (DRM) is an umbrella term for any of several arrangements which allows a vendor of content in electronic form to control the material and restrict its usage in various ways that can be specified by the vendor. ...

Attribution, disclaimers, notices

Most free software licences require that when a modified version of the software is distributed, it does not claim to be an unmodified version. Some licences also require that the copyright holders be credited.

An example is that version 2 of the GNU GPL requires that if an interactive program prints warranty or licence information, modified versions cannot be distributed if they remove those notices.

Unacceptable restrictions

While protecting the four freedoms allows adding certain restrictions, restrictions on private use of the software ("use restrictions") are generally unacceptable. Examples include prohibiting the software to be used for military purposes, for comparison or benchmarking, or in commercial organisations.

BSD philosophy

Many users and developers of BSD-based operating systems have a different position on licensing. The main difference is the belief that the copyleft licenses, particularly the GNU General Public License (GPL), are too complicated and have restrictions which are undesirable. The GPL requires derivative work to be released according to the GPL while the BSD licence does not. Essentially, the BSD license's only requirement is to acknowledge the original authors, and poses no restrictions on how the source code may be used. As a result, BSD code can find its way into proprietary software that only acknowledge the source. For instance, the IP stack in Microsoft Windows and Mac OS X are derived from BSD-licensed software. Two of the most common free software licenses are the BSD license and the GNU General Public License license (GPL). ... Berkeley Software Distribution (BSD, sometimes called Berkeley Unix) is the Unix derivative distributed by the University of California, Berkeley, starting in the 1970s. ... The reversed c is the copyleft symbol. ... The GNU logo The GNU General Public License (GNU GPL or simply GPL) is a widely used free software license, originally written by Richard Stallman for the GNU project. ... Source code (commonly just source or code) is any series of statements written in some human-readable computer programming language. ... Proprietary software is software that has restrictions on using and copying it, usually enforced by a proprietor. ... The internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet and most commercial networks run. ... Microsoft Windows is a family of operating systems by Microsoft. ... Mac OS X (IPA pronunciation: ) is a line of proprietary, graphical operating systems developed, marketed, and sold by Apple Computer, the latest of which is pre-loaded on all currently shipping Macintosh computers. ...

GPL supporters claim that mandating derivative works remain free fosters the growth of free software and requires equal participation by all users. Developers who use GPL code have to share their improvements with the community, supporting the growth of the software they received.

Supporters of the BSD license argue that it is more free than the GPL because it grants the right to do anything with the source code, second only to software in the public domain. The nature of BSD has encouraged the inclusion of well-developed standard code into proprietary software. In response, GPL supporters claim that this is more a form of power than a freedom.[2] The right to make closed-source code is therefore not included in the Free Software Foundation's "four freedoms of free software"; using, studying, copying, and distributing modifications of the code. The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... The Free Software Foundation logo The Free Software Foundation (FSF) is a non-profit organization founded in October 1985 by Richard Stallman to support the free software movement (free as in freedom), and in particular the GNU project. ...

Code licensed under the BSD license can be relicensed under the GPL (is "GPL-compatible") without securing the consent of all original authors. Code under the GPL cannot be relicensed under the BSD license without securing the consent of all copyright holders, as the BSD license is not copyleft and therefore GPL is "BSD-incompatible". Existing free software BSDs tend to avoid including software licensed under the GPL in the core operating system, or the base system, except as a last resort when alternatives are non-existent or vastly less capable, such as with GCC. The OpenBSD project has acted to remove GPL-licensed tools in favour of BSD-licensed alternatives, some newly written and some adapted from older code. The GNU Compiler Collection (usually shortened to GCC) is a set of programming language compilers produced by the GNU Project. ... OpenBSD is a freely available Unix-like computer operating system descended from Berkeley Software Distribution (BSD), a Unix derivative developed at the University of California, Berkeley. ...

Debian

The Debian project uses the criteria laid out in its Debian Free Software Guidelines (DFSG). The only notable cases where Debian and Free Software Foundation disagree are over the Artistic License and the GNU Free Documentation License. Debian accept the original Artistic License as being a free software license, but FSF disagree. This has very little impact however since the Artistic License is almost always used in a dual-license setup, along with the GNU General Public License. Debian, organized by the Debian Project, is a widely used distribution of free software developed through the collaboration of volunteers from around the world. ... The Debian Free Software Guidelines (DFSG) are a set of guidelines that the Debian Project uses to determine whether a software license is free software license, which in turn is used to determine whether a piece of software can be included in the main, free software distribution of Debian. ... The Artistic License is a software license used for certain free software packages, most notably the standard Perl implementation, most of CPAN modules and Parrot, which are dual-licensed under the Artistic License and the GNU General Public License (GPL). ... GNU logo (similar in appearance to a gnu) The GNU Free Documentation License (GNU FDL or simply GFDL) is a copyleft license for free content, designed by the Free Software Foundation (FSF) for the GNU project. ... Licenses are granted by copyright holders to grant exceptions of copyright law to users for a work. ... The GNU logo The GNU General Public License (GNU GPL or simply GPL) is a widely used free software license, originally written by Richard Stallman for the GNU project. ...

Regarding the GNU Free Documentation License, Debian argues that the DFSG applies to documentation as it does on software, and so documentation licenses must be examined against these free software guidelines. FSF say that documentation is qualitatively different from software and is subject to different requirements. The end result of a long discussion and the eventual vote in Debian[3] is that the works licensed under the GFDL are considered free as long as they do not contain unmodifiable sections (Invariant Sections). GNU logo (similar in appearance to a gnu) The GNU Free Documentation License (GNU FDL or simply GFDL) is a copyleft license for free content, designed by the Free Software Foundation (FSF) for the GNU project. ...

See also

Free software Portal

• Free software movement
• Free software
• Copyleft
• DFSG

Image File history File links Floss_draft. ... The free software movement began in 1983 when Richard Stallman announced the GNU project. ... This article is about free software as defined by the sociopolitical free software movement; for information on software distributed without charge, see freeware. ... The reversed c is the copyleft symbol. ... The Debian Free Software Guidelines (DFSG) are a set of guidelines that the Debian Project uses to determine whether a software license is free software license, which in turn is used to determine whether a piece of software can be included in the main, free software distribution of Debian. ...

External links

• The Free Software Definition (Free Software Foundation).
• The Free Software Foundation's list of free and unfree licenses
• Debian's license information page
• Open Source Initiative's list of license
• OpenBSD's "goals" page describes its view of free software
• Transcripts of licence strategy discussions by Stallman and Moglen during the drafting of GPLv3
• International Open Source Network Free/Open Source Software Licensing - Available as a Wikibook
• Forfás Report on free software business models and licensing (58 pages)