Affero General Public License
Encyclopedia
The Affero General Public License, often abbreviated as Affero GPL and AGPL (and sometimes informally called the Affero License), refers to two distinct, though historically related, free software licenses:
Both versions of the AGPL were designed to close a perceived application service provider
"loophole" (the "ASP loophole") in the ordinary GPL, where by using but not distributing the software, the copyleft
provisions are not triggered. Each version differs from the version of the GNU GPL on which it is based in having an additional provision addressing use of software over a computer network. The additional provision requires that the complete source code be made available to any network user of the AGPL-licensed work, typically a Web application
.
The Free Software Foundation
has recommended that the GNU AGPLv3 be considered for any software that will commonly be run over a network. The Open Source Initiative
approved the GNU AGPLv3 as an open source
license in March 2008 after Funambol
submitted it for consideration.
in Amsterdam where they discussed the ASP
loophole in GPLv2. Over the following months, Stallman and Poole discussed approaches to solving the problem. In 2001, Poole founded Affero, Inc. (a web services business), and he needed a license that would require distribution by other organizations who used Affero code to create derivative web services. At that time, Poole contacted Bradley M. Kuhn
and Eben Moglen
of the Free Software Foundation
to get advice on a new license that would close the ASP loophole in GPLv2.
Around late February 2002, Kuhn suggested, based on the idea of a program that prints its own source code, that GPLv2 be supplemented with a section 2(d) that would require derivative works to maintain a "download source" feature that would provide complete and corresponding source code. Kuhn argued that there was precedent for such a requirement in GPLv2 section 2(c), which required preservation of certain features by downstream distributors and modifiers.
Moglen and Kuhn wrote the text of the proposed new section 2(d), and provided it to Poole, who then requested and received permission from the FSF to publish a derivative of GPLv2 for this purpose. In March 2002, Affero, Inc. published the original Affero General Public License (AGPLv1) for use with the Affero project and made the new license available for use by other software-as-a-service developers.
The FSF contemplated including the special provision of AGPLv1 into GPLv3 but ultimately decided to publish a separate license, nearly identical to GPLv3 but containing a provision similar in purpose and effect to section 2(d) of AGPLv1. The new license was dubbed the GNU Affero General Public License, the retention of the Affero name indicating its close historical relationship with AGPLv1. The GNU AGPL was given version number 3 for parity with the GPL, and the current GNU Affero General Public License is often abbreviated AGPLv3.
The finalized version of AGPLv3 was published by the FSF on November 19, 2007.
Stet
is the first software system known to be released under AGPLv3 (on November 21, 2007), and is the only known program to be used primarily for the production of its own license.
with the otherwise nearly identical GPLv2. That is to say, one cannot distribute a single work formed by
combining components covered by each license.
By contrast, GPLv3 and AGPLv3 each include clauses (in section 13 of each license) that together achieve a form of mutual compatibility for the two licenses. These clauses explicitly allow the "conveying" of a work formed by linking code licensed under the one license against code licensed under the other license, despite the licenses otherwise not allowing relicensing under the terms of each other. In this way, the copyleft of each license is relaxed to allow distribution of such combinations.
To establish an upgrade path from AGPLv1 to the FSF's AGPLv3, Affero, Inc. published the Affero General Public License version 2, which is merely a transitional license that allows recipients of software licensed under "AGPLv1 or any later version as published by Affero, Inc." to distribute the software, or derivative works, under AGPLv3.
(the successor of Stet
), the develop and maintain software launchpad
, the distributed social networking services Diaspora
and StatusNet, and the network monitoring application Shinken
.
Both versions of the AGPL were designed to close a perceived application service provider
Application service provider
An application service provider is a business that provides computer-based services to customers over a network. Software offered using an ASP model is also sometimes called On-demand software or software as a service ....
"loophole" (the "ASP loophole") in the ordinary GPL, where by using but not distributing the software, the copyleft
Copyleft
Copyleft is a play on the word copyright to describe the practice of using copyright law to offer the right to distribute copies and modified versions of a work and requiring that the same rights be preserved in modified versions of the work...
provisions are not triggered. Each version differs from the version of the GNU GPL on which it is based in having an additional provision addressing use of software over a computer network. The additional provision requires that the complete source code be made available to any network user of the AGPL-licensed work, typically a Web application
Web application
A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is coded in a browser-supported language and reliant on a common web browser to render the application executable.Web applications are...
.
The Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
has recommended that the GNU AGPLv3 be considered for any software that will commonly be run over a network. The Open Source Initiative
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...
approved the GNU AGPLv3 as an open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
license in March 2008 after Funambol
Funambol
Funambol is an American corporation that earns revenue from its dual-licensing business model that includes commercial software and free open source mobile data synchronization software based on the Funambol core project.-Funambol-based companies:...
submitted it for consideration.
History
In 2000, while developing an e-learning and e-service business model, Henry Poole met with Richard StallmanRichard Stallman
Richard Matthew Stallman , often shortened to rms,"'Richard Stallman' is just my mundane name; you can call me 'rms'"|last= Stallman|first= Richard|date= N.D.|work=Richard Stallman's homepage...
in Amsterdam where they discussed the ASP
Application service provider
An application service provider is a business that provides computer-based services to customers over a network. Software offered using an ASP model is also sometimes called On-demand software or software as a service ....
loophole in GPLv2. Over the following months, Stallman and Poole discussed approaches to solving the problem. In 2001, Poole founded Affero, Inc. (a web services business), and he needed a license that would require distribution by other organizations who used Affero code to create derivative web services. At that time, Poole contacted Bradley M. Kuhn
Bradley M. Kuhn
Bradley M. Kuhn is a free software activist from the United States.Kuhn is currently Executive Director of the Software Freedom Conservancy. Until 2010 he was the FLOSS Community Liaison and Technology Director of the Software Freedom Law Center . He previously served as the Executive Director of...
and Eben Moglen
Eben Moglen
Eben Moglen is a professor of law and legal history at Columbia University, and is the founder, Director-Counsel and Chairman of Software Freedom Law Center, whose client list includes numerous pro bono clients, such as the Free Software Foundation....
of the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
to get advice on a new license that would close the ASP loophole in GPLv2.
Around late February 2002, Kuhn suggested, based on the idea of a program that prints its own source code, that GPLv2 be supplemented with a section 2(d) that would require derivative works to maintain a "download source" feature that would provide complete and corresponding source code. Kuhn argued that there was precedent for such a requirement in GPLv2 section 2(c), which required preservation of certain features by downstream distributors and modifiers.
Moglen and Kuhn wrote the text of the proposed new section 2(d), and provided it to Poole, who then requested and received permission from the FSF to publish a derivative of GPLv2 for this purpose. In March 2002, Affero, Inc. published the original Affero General Public License (AGPLv1) for use with the Affero project and made the new license available for use by other software-as-a-service developers.
The FSF contemplated including the special provision of AGPLv1 into GPLv3 but ultimately decided to publish a separate license, nearly identical to GPLv3 but containing a provision similar in purpose and effect to section 2(d) of AGPLv1. The new license was dubbed the GNU Affero General Public License, the retention of the Affero name indicating its close historical relationship with AGPLv1. The GNU AGPL was given version number 3 for parity with the GPL, and the current GNU Affero General Public License is often abbreviated AGPLv3.
The finalized version of AGPLv3 was published by the FSF on November 19, 2007.
Stet
Stet (software)
stet is a free software package for gathering comments about a text document via a webpage.-History:The initial version was developed from late 2005 until mid-2006 by the Software Freedom Law Center as a service to its client, the Free Software Foundation...
is the first software system known to be released under AGPLv3 (on November 21, 2007), and is the only known program to be used primarily for the production of its own license.
Compatibility with the GPL
Both versions of the AGPL, like the corresponding versions of the GNU GPL on which they are based, are strong copyleft licenses. In the FSF's judgment, the additional requirement in section 2(d) of AGPLv1 made it incompatibleLicense compatibility
License compatibility refers to the problem with licenses applied to works subject to copyright, particularly licenses of software packages, which can contain contradictory requirements, rendering it impossible to combine source code from such packages or content from such works in order to create...
with the otherwise nearly identical GPLv2. That is to say, one cannot distribute a single work formed by
combining components covered by each license.
By contrast, GPLv3 and AGPLv3 each include clauses (in section 13 of each license) that together achieve a form of mutual compatibility for the two licenses. These clauses explicitly allow the "conveying" of a work formed by linking code licensed under the one license against code licensed under the other license, despite the licenses otherwise not allowing relicensing under the terms of each other. In this way, the copyleft of each license is relaxed to allow distribution of such combinations.
To establish an upgrade path from AGPLv1 to the FSF's AGPLv3, Affero, Inc. published the Affero General Public License version 2, which is merely a transitional license that allows recipients of software licensed under "AGPLv1 or any later version as published by Affero, Inc." to distribute the software, or derivative works, under AGPLv3.
Examples of web applications under AGPL
Some of the best-known examples of AGPL software include the collaborative online word processor Co-mentCo-ment
co-ment is an online word processor allowing collaborative work on text writing. It's the descendant of the tool created to handle the GNU GPL version 3 online revision. It is freely available under Affero GPL.- Description :...
(the successor of Stet
Stet
Stet is a Latin word used by proofreaders and editors to instruct the typesetter or writer to disregard a change the editor or proofreader had previously marked....
), the develop and maintain software launchpad
Launchpad
A launch pad is the area and facilities where rockets or spacecraft take off.Launch pad may also refer to:-Computing:* Launchpad , website used for bug tracking and software development mainly used as part of the Ubuntu operating system...
, the distributed social networking services Diaspora
Diaspora (software)
Diaspora is a free personal web server that implements a distributed social networking service. Installations of the software form nodes which make up the distributed Diaspora social network....
and StatusNet, and the network monitoring application Shinken
Shinken
is a Japanese term used to describe a Japanese sword that is sharp and used for real cutting or combat, as opposed to those that are blunted for other types of practice. Today, they are primarily used for high level iaido and/or tameshigiri practice. Unlike an iaito or mogito , a shinken has a...
.
See also
- List of AGPL web applications
- Free Software licensing
- GNU General Public LicenseGNU General Public LicenseThe GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
- GNU Lesser General Public LicenseGNU Lesser General Public LicenseThe GNU Lesser General Public License or LGPL is a free software license published by the Free Software Foundation . It was designed as a compromise between the strong-copyleft GNU General Public License or GPL and permissive licenses such as the BSD licenses and the MIT License...
- GNAT Modified General Public LicenseGNAT Modified General Public LicenseThe GNAT Modified General Public License is a version of the GNU General Public License specifically modified for the generic feature found in the Ada programming language.The modification is as follows:...
- GPL linking exceptionGPL linking exceptionA GPL linking exception modifies the GNU General Public License to create a new, modified license. Such modified licenses enable software projects which provide library code, to be "linked to" the programs that use them, without applying the full terms of the GPL to the using program...
- GNU Free Documentation LicenseGNU Free Documentation LicenseThe GNU Free Documentation License is a copyleft license for free documentation, designed by the Free Software Foundation for the GNU Project. It is similar to the GNU General Public License, giving readers the rights to copy, redistribute, and modify a work and requires all copies and...
- List of software licenses