GPL (General Public License), also known as GNU GPL, is one of the most widely used free software licenses in the world. It was created by Richard Stallman for the GNU Project under the Free Software Foundation.

WordPress itself is released under the GPL license, which means it is open-source software that can be freely used, modified, and extended by anyone. Because of this, WordPress themes, plugins, and extensions that are built for WordPress are typically released under the GPL or a compatible license.

At WPXStore, we support the core principles of the GPL and the open-source ecosystem.

What the GPL Allows

The GPL license is designed to protect user freedom. Under the GPL, users have the right to:

  • Download and run the software for any purpose
  • Study, modify, and adapt the source code
  • Redistribute original copies of the software
  • Redistribute modified versions of the software

These freedoms ensure that software remains open, transparent, and accessible to everyone.

Understanding Copyright and Copyleft

Copyright is a legal concept that gives creators control over how their work is used, modified, and shared. The GPL uses a concept known as “copyleft.”

When a developer releases software under a copyleft license like the GPL, they retain copyright ownership but grant others the freedom to use, modify, and distribute the software—provided that the same freedoms are preserved in any redistributed versions.

This means that software derived from GPL-licensed code must also remain open-source if it is distributed.

Can GPL Products Be Sold?

Yes. GPL-licensed software can be sold.

The term “free software” refers to freedom, not price. As explained by Richard Stallman, free software means “free as in free speech,” not “free as in free beer.” You are allowed to charge for GPL software, including original or modified versions, as long as GPL terms are respected.

Is GPL Safe?

Yes. The GPL license itself does not affect security or functionality. It is a legal license that governs how software can be used, modified, and shared. The safety of any software depends on its code quality and maintenance, not on the license alone.

Do You Have to Release Modified Source Code?

Under the GPL, you are required to release modified source code only if you distribute the modified software.

If you modify GPL-licensed software for personal or internal use and do not distribute it, there is no obligation to release those changes publicly.

GPLv2 vs GPLv3

There is often confusion between GPL version 2 and GPL version 3.

GPLv3 was created to clarify when license obligations apply and to address modern legal and technical challenges. It also improves compatibility with other open-source licenses, allowing developers greater flexibility when combining code from different projects.

GPLv3 was written with international usage in mind. Its language was updated to better align with global legal systems, whereas GPLv2 is considered more focused on United States legal terminology. GPLv3 also allows additional local disclaimers, helping adoption worldwide.

GPL License Terms and Conditions

Under the GPL:

  • You may not claim exclusive copyright or patents over GPL-licensed software
  • Copyright notices, license text, and disclaimers must remain intact
  • You may not change the license or add additional restrictions
  • Source code must be made available when distributing the software
  • Users must retain the right to modify and redistribute the software

These conditions ensure that software remains free and open for future users.