The plugin directory’s licensing guidelines have been updated…

The pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the Plugin Directory or can be cost-based plugin from a third-party directory’s licensing guidelines have been updated. The guidelines will now allow code that is licensed under (or compatible with) version 3 of the GPLGPL GNU General Public License. Also see copyright license..

The guidelines still encourage use of “GPLv2 or later,” the same license as WordPress. However, we understand that many open sourceOpen Source Open Source denotes software for which the original source code is made freely available and may be redistributed and modified. Open Source **must be** delivered via a licensing model, see GPL. libraries use other licenses that are nonetheless compatible, such as GPLv2 only, GPLv3, and ApacheApache Apache is the most widely used web server software. Developed and maintained by Apache Software Foundation. Apache is an Open Source software available for free. 2.0.

Now may be a good time for plugin authors to review their plugins to ensure a license is specified. You can add License and License URI headers to readme.txt and the plugin’s headers. (You may also wish to include a copying permission statement.) For example:

License: GPLv2 or later
License URI:

You can see this used in the sample readme.txt.

This change brings the guidelines in line with the themes directory, which has for some time accepted GPLv3-compatible code. (Probably a good time to note that Creative Commons licenses are still incompatible with the GPL, and the theme and plugin directories.)

#gpl, #plugin-directory

Clarification in Licensing Language

WordPress has always stated that its license was the GNU GPLGPL GNU General Public License. Also see copyright license., and has bundled version 2 of the license, even though no GPL version was specified. The text of version 2 (as well as 1 and 3) says that if no version is specified, the software can be redistributed under the terms of any version of the GPL published by the FSF.

However, WordPress contains libraries which are licensed under the GPL “version 2 or any later version,” which obviously excludes version 1 of the GPL. Here is the reality: the GPL version 1 is effectively irrelevant. It hasn’t been a commonly used license since before Matt Mullenweg was in third grade! Clarifying WordPress as being licensed under the GPL “version 2 or later” resolves these niggling library licensing concerns or ambiguities, and clarifies where WordPress stands.

It was the intention of the WordPress founders and developers to be GPL version 2 or later from the beginning, and we have now made that license properly explicit.