Understanding the GPL License

The GNU General Public License (GPL) is a widely adopted free software license that ensures end users have the freedom to use, study, share, and modify software. Originally authored by Richard Stallman for the GNU Project, the GPL powers much of today’s open-source ecosystem — including WordPress.

Core Principles of GPL

  • Freedom to use software for any purpose
  • Freedom to examine and alter the source code
  • Freedom to share original software with others
  • Freedom to distribute modified versions

Common GPL Questions

1. What does “copyleft” mean?

Copyleft is a licensing concept that ensures derivative works of open-source software remain open. When software is released under the GPL, any redistributed versions — modified or not — must also be licensed under the GPL. This keeps the software ecosystem open and collaborative.

2. Can GPL software be sold?

Yes. The GPL allows anyone to sell original or modified versions of the software. However, they must provide the source code and comply with the license terms. “Free” in GPL refers to freedom, not price — as famously said, “free as in speech, not free as in beer.”

3. Is it legal to redistribute GPL products?

Absolutely. Redistribution — both paid and free — is a core right under the GPL. As long as the license terms are followed, anyone can distribute GPL software, including themes, plugins, and tools derived from GPL projects.

4. Am I required to release modifications I make?

If you modify GPL software for personal use, you are not required to release your changes. However, if you distribute the modified version, you must make the source code and modifications publicly available under the same license.

5. What’s the difference between GPLv2 and GPLv3?

While both versions uphold the same basic freedoms, GPLv3 includes stronger protections against:

  • Tivoization (restricting modified software on hardware)
  • Patent deals and DRM restrictions
  • Improved international legal clarity and compatibility with other licenses

6. What are the main requirements under GPL?

  • You must include a copy of the GPL license with the software
  • Include a disclaimer of warranty
  • Provide access to the source code
  • Keep copyright notices intact
  • Do not impose additional restrictions on redistribution

Why GPL Matters for WordPress and Digital Products

WordPress itself is licensed under the GPL, meaning all derivative works (like plugins and themes) are also governed by the GPL. This ensures a community-driven ecosystem where innovation is shared and accessible to everyone.

Is GPL Safe?

Yes. The GPL does not affect how the software functions. It only governs how the code can be used and shared. As long as a product comes from a trusted source, using GPL software is just as safe as using any commercial license.

Disclaimer

The information above is for educational purposes and should not be considered legal advice. For legal interpretation, consult a qualified attorney familiar with open-source licensing.

Need Help?

If you have questions about GPL, WordPress licensing, or open-source distribution, feel free to reach out at [email protected].