“WordPress is available completely free of charge under the GPL license. Enjoy!”
The GPL, or GNU General Public License, is one of the most radical “copyleft” licenses software can be published under. It embeds in the software itself the “four freedoms that every user should have:
- the freedom to use the software for any purpose,
- the freedom to change the software to suit your needs,
- the freedom to share the software with your friends and neighbors, and
- the freedom to share the changes you make.