License proliferation

License proliferation refers to the problems created when additional software licenses are written for software packages. License proliferation affects the free software community. Often when a software developer would like to merge portions of different software programs they are unable to do so because the licenses are incompatible. When software under two different licenses can be combined into a larger software work, the licenses are said to be compatible. As the number of licenses increases, the probability that a FOSS developer will want to merge software together that are available under incompatible licenses increases. There is also a greater cost to companies that wish to evaluate every FOSS license for software packages that they use. Strictly speaking no one is in favor of license proliferation. Rather the issue stems from the tendency for organizations to write new licenses in order to address real or perceived needs for their software releases.

Compatible licenses

The Free Software Foundation who maintains the GNU General Public License (GPL) also maintains a [http://www.gnu.org/philosophy/license-list.html list of the licenses that are compatible with the GPL] . Another popular FOSS license is the Apache License, the Apache Foundation has a page discussing the fact that the [http://www.apache.org/licenses/GPL-compatibility.html Apache License is listed as incompatible with the GPL] .

Vanity licenses

Vanity licenses is a term that refers to a license that is written by a company or person for no other reason than to write their own license. If a new license is created that has no obvious improvement or difference over another more common FOSS license it can often be criticized as a vanity license.

Google's stance

To limit license proliferation, Google limits the licenses that its source repository system would accept to the following: [ [http://blogs.zdnet.com/Burnette/?p=192 interview regarding Google's decision to fight license proliferation] ]
* Apache License 2.0
* Artistic License/GPL (often used by the Perl community)
* GNU General Public License 3.0
* GNU General Public License 2.0
* GNU Lesser General Public License
* MIT License
* New BSD License
* Mozilla Public License 1.1
* Eclipse Public License

They also highly recommend choosing the Apache License or GPLv3 for projects. [ [http://google-opensource.blogspot.com/2008/05/standing-against-license-proliferation.html Google Open Source Blog: Standing Against License Proliferation ] ]

OSI's stance

Open Source Initiative (OSI) consider themselves the keepers of what licenses can be called open source. They maintain a list of licenses that are [http://opensource.org/licenses/alphabetical OSI Approved Licenses] , and early in their history, contributed some to license proliferation by assisting in the production and approving vanity licenses. Indeed, some including Mark Shuttleworth argue that the [http://www.markshuttleworth.com/archives/67 OSI is largely responsible for the license proliferation problem] by continuing to accept new licenses. However, the OSI started the [http://opensource.org/proliferation License Proliferation Project] which is working on a [http://opensource.org/osi3.0/proliferation-report License Proliferation Report] which is intended to address some of the issues with license proliferation.

FSF's stance

Richard Stallman, president of FSF, and Bradley M. Kuhn, former Executive Director, have argued against license proliferation since 2000, when they instituted the FSF "license list", which urged developers to use only licenses considered GPL compatible. [The earliest archived version of the license list reflects this position. cite news | author=Bradley M. Kuhn | authorlink=Bradley M. Kuhn | title=Various Licenses and Comments about Them | url=http://www.gnu.org/philosophy/license-list.html | format=HTML | publisher=Free Software Foundation | pages= 37–39 | date=2000-08-15 | accessdate=2000-08-15 | archiveurl=http://web.archive.org/web/20000815065020/http://www.gnu.org/philosophy/license-list.html | archivedate=2008-07-04 ]

FSF Europe's Stance

Ciaran O'Riordan argues that the main thing that the FSF can do to prevent license proliferation is to reduce the reasons for making new licenses in the first place, in an editorial entitled [http://www.linuxdevices.com/articles/AT7188273245.html How GPLv3 tackles license proliferation] . Generally the FSF Europe consistently recommends the use of the GNU GPL as much as possible, and when that is not possible, to use GPL-compatible licenses.

See also

* License compatibility

External links

* [http://www.ipinfoblog.com/archives/licensing-law-issues-open-source-license-proliferation-a-broader-view.html Open source license proliferation, a broader view] by Raymond Nimmer
* [http://old.linux-foundation.org/newsroom/articles/License_Proliferation.pdf Larry Rosen argues that different licenses can be a good thing] Larry Rosen
* [http://www.catb.org/~esr/Licensing-HOWTO.html Licensing howto] by Eric Steven Raymond
* [http://www.freesoftwaremagazine.com/columns/sharing_medical_software_foss_licensing_in_medicine License proliferation for Medical Software] by [http://www.fredtrotter.com Fred Trotter] Advocates that for Health Software, only the Google seven should be used.

References