The plugin 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 WordPress.org Plugin Directory https://wordpress.org/plugins/ 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 GPL 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 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 Apache 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: http://www.gnu.org/licenses/gpl-2.0.html
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.)