Joomla! License FAQ

What license does Joomla! use?

The GNU General Public License Version 2 or later. http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
Within the context of this FAQ, "GNU GPL" and "GPL" refer to the GNU General Public License Version 2.

What is the difference between the GPL and the LGPL?

The GNU GPL is intended to be used for applications whereas the GNU LGPL is intended to be used for application libraries.  The Joomla! Content Management System is an entire application that utilizes a multitude of libraries, both GPL and LGPL (as well as with other GPL compatible licenses), and thus is licensed under the GPL license.

Where can I read more about the license?

The GNU General Public License: http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
The GNU GPL Frequently Asked Questions (FAQ): http://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html
The philosophy behind the GNU: http://www.gnu.org/philosophy/

 

What is the definition of Open Source/Free Software?

http://en.wikipedia.org/wiki/Open_source
http://en.wikipedia.org/wiki/Free_software

 

What is meant by "voluntary compliance?"

We want all parties to come into compliance with our license, as it strengthens our ability to defend and protect Joomla!  We do not have the will nor the means to go after everyone who violates our license nor do we intend to.  We are asking the community to voluntarily comply with the GPL.

What is the difference between "commercial" and "proprietary"?

Commercial software means that there is some sort of commercial activity surrounding that software.  It could be a business that develops it and charges money for distribution, support, documentation, customization, etc.  Commercial software is not necessarily proprietary software and proprietary software is not necessarily commercial software.  Proprietary software means that you do not have the right to copy, modify, and redistribute that software. 

See: http://en.wikipedia.org/wiki/Proprietary_software

 

Does the license allow someone to sell a copy of Joomla!?

Yes.  The Preamble of the GNU GPL states "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 this service 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." 

Also see: http://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html#DoesTheGPLAllowMoney

 

Can I remove the Joomla! Copyright notice in the footer region (and other related questions)?

Yes, you can remove the Joomla! copyright notices from any part of the output that the Joomla! application generates.  You may not remove the copyright notice from the source code itself.

 

Can I remove the Joomla! Copyright notice in the Meta information of a Joomla! website?

Yes, you can remove the copyright notices from any part of the output that the Joomla! application generates.  You may not remove the copyright notice from the source code itself.

 

What should I do if I find a possible violation of the GPL?

You should report the possible violation to the appropriate copyright holders.  If you believe someone is violating the GPL license of the people who develop the Joomla! project please report the violation by e-mail to This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

 

Extensions

Does the license allow someone to sell an extension?

Yes.  The Preamble of the GNU GPL states "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 this service 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."

Also see: http://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html#DoesTheGPLAllowMoney

 

Does the license allow someone to encrypt an extension?

Yes, technically, but the distributor must provide access to the complete and unencrypted source code by either including it in the package or by making it available for download.  The distributor must provide access "for a charge no more than [their] cost of physically performing source distribution."  See [1].

Can I release an extension under a non-GPL licence?

It is our opinion that most extensions are derivative works of Joomla! and must be licensed under the GNU GPL.  It is possible that an extension could work within Joomla! and not be considered a derivative work according to copyright law but this would have to be evaluated on a case-by-case basis.  If you believe your extension is not a derivative work we strongly recommend that you seek professional legal advice.

How does the treatment of templates differ from the treatment of components, modules, and plugins?

In our opinion, templates are composite packages that consist of both code elements and non-code elements.  We believe that the code elements of a template must be licensed under the GNU GPL because they are derivative works.  However, the non-code elements are just data acted upon by the software and may be licensed in any way the author sees fit.  The non-code elements include elements like Images, Movies, Animations, CSS and formatting markup.

Please see: "Does JavaScript included in templates and extensions need to be licensed under the GPL? " and "Does the CSS in my template need to be licensed under the GPL? "

What is the difference between a bridge to another package and an extension?

A bridge links Joomla! to an external application so that they can exchange data and cooperate. On the Joomla! side of the bridge, the bridge is treated just like a component, module, or plugin; it must comply with the GPL unless it is a separate work (and some bridges might indeed be separate works).

If the external application is separate enough from Joomla! that it is a separate work under copyright law, it may be licensed under whatever license the holder of its copyright sees fit.

Does the CSS in my template need to be licensed under the GPL?

Not unless it is based on work that is licensed under the GNU GPL.  See [1].

Does JavaScript included in templates and extensions need to be licensed under the GPL?

Not unless it is based on work that is licensed under the GNU GPL. See [1].

If I include a module in a template, does it need to be under the GPL license?

Generally, yes. See "Can I release an extension under a non-GPL license? "

I purchased a copy of an extension that violates the Joomla! licence.  Can I now distribute it under the GPL?

No.  You should report the violation to the appropriate copyright holders.

Can I offer a hosted service with my custom, proprietary extensions?

Yes.  The GNU GPL does not apply until you attempt to distribute your custom extensions to an outside party.  If you decide to distribute your extensions, they will need to be licensed under the GNU GPL.

New addition:

Can I release an extension under a GPL Compatible license?

Joomla! or a Joomla! extension may incorporate a building block that has a compatible license because the building block can be effectively relicensed as GPL for purposes of the application (without of course changing the license for other applications using the same library). That is because those licenses are less restrictive and the Joomla! application adds the GPL restrictions for any use of those libraries within the Joomla! application. As the FSF explains on its website

All GNU GPL versions permit such combinations privately; they also permit distribution of such combinations provided the combination is released under the same GNU GPL version. The other license is compatible with the GPL if it permits this too.

Extensions extend and derive from Joomla! and Joomla! is GNU GPL. Therefore extensions cannot be licensed with a less restrictive license. They can't give their users and subsequent users fewer rights than they would have under the GPL. GPL compatible licenses do not guarantee that subsequent users will be given the same rights as current users. Therefore their use in work derived from Joomla! violates the terms under which the copyright holders have licensed their code, which are the terms of the GNU GPL.

For more than two years the Joomla! Project has clearly stated that in its view and the views of the legal experts we have consulted extensions are almost always derivative works for Joomla and must therefore be licensed using the GNU GPL.

See the following for useful commentary:
http://www.fsf.org/licensing/licenses/gpl-faq.html
http://wordpress.org/development/2009/0 ... e-gpl-too/

Footnotes:

[1] The Joomla! project is no substitute for an attorney.  If you have specific legal questions that require precise answers we strongly suggest you attain legal counsel in your own jurisdiction.