What Is GPL?

The General Public License (GPL), also known as GNU GPL, is the most widely used free software license. Created by Richard Stallman for the GNU Project under the Free Software Foundation, it allows software to be freely used, modified, and redistributed by anyone. WordPress is an example of software under the GPL, meaning it is open-source and can be used, modified, and extended by anyone.

The GPL upholds the project’s core values:

• Anyone can download and run the software.
• Anyone can modify or edit the software.
• Anyone can redistribute free copies of the software.
• Anyone can distribute modified versions of the software.

You may have heard of the GPL, but you might not fully grasp its impact on the WordPress platform and community.

WordPress and GPL

WordPress, along with thousands of other software programs, is licensed under the GPL.

The GPL license greatly benefits WordPress, contributing to its status as the most popular CMS software today. The GPL allows public access to all WordPress files, enabling developers worldwide to study, modify, and enhance the code.

This accessibility has fostered a large, vibrant community around WordPress, generating excitement and encouraging more people to use and contribute to the software. As a result, over 36% of the world’s websites now use WordPress as their CMS platform—a remarkable statistic made possible by the GPL.

Additionally, WordPress holds over 70% of the market share among CMS platforms. Despite other CMS platforms being developed around the same time, their lack of GPL licensing hindered their growth and allowed WordPress to achieve a significant lead in usage and popularity.

Matt Mullenweg, the co-founder of WordPress, is a strong advocate of the GPL. He has stated, “If WordPress were a country, our Bill of Rights would be the GPL because it protects our core freedoms.

Matt Mullenweg firmly believes that for software to thrive, it should be released under the GPL. This commitment is central to WordPress, which embraces the GPL as its guiding “Bill of Rights.”

Over the years, many competitors of WordPress that did not adopt the GPL disappeared. Without a robust user base, these platforms struggled to survive as users migrated to more developed software, like WordPress, which benefitted from continuous improvements under the GPL.

The GPL, a software license that allows for freedom in using, modifying, and distributing software, has been instrumental in WordPress’s success. It has enabled WordPress to evolve into the most widely used CMS platform globally, serving millions of users.

Now, let’s address some common questions about the GPL:

Top 5 GPL License Questions Answered

1. What is copyleft?
   Copyleft is a principle within the GPL that ensures any software based on GPL-licensed code must also be released as open-source. This mandates that the source code and modification rights are freely available to all users.

2. Can you sell GPL products?
   Yes, the GPL allows for selling both original and modified products. “Free” in the context of free software refers to freedom of use, not necessarily free of cost.

3. Is GPL safe?
   Yes, the GPL is a license governing usage and distribution rights, unrelated to the safety or security of the software’s source code.

4. Does the GPL license require the author to release modified source code?
   Under the GPL, modified source code must be released only if the modified program itself is distributed. Personal modifications not distributed do not require source code release.

5. What is the difference between GPLv2 & GPLv3?
   GPLv3 clarified obligations related to the “ASP loophole” and improved compatibility with other licenses. It also aimed to ensure global applicability by adjusting language to align with international legal interpretations.

In conclusion, the GPL ensures software remains open for modification and distribution while setting clear terms for usage and sharing. It promotes innovation and community collaboration, key factors in WordPress’s widespread adoption and success.

Furthermore, the FSF has enhanced GPLv3 to improve compatibility with other licenses. For two codes to merge into a larger work, both applications must permit it. Compatibility exists if both licenses grant these rights. These adjustments expand development opportunities.

Another difference is GPLv3’s global focus. Its language was revised to ensure international laws interpret it as intended by the FSF. In contrast, GPLv2 was criticized for its US-centric wording. GPLv3 also allows developers to add local disclaimers, enhancing its global appeal.

Regarding GPL terms and conditions:

• Patents or copyright claims on the product are not permitted.
• Requirements include displaying a copyright notice, disclaimer of warranty, intact GPL notices, and a copy of the GPL.
• Modifying the license or adding additional terms is prohibited.
• You must release the source code and grant rights to modify and distribute the entire code.

Note: This information is provided as-is and should not be construed as legal advice. If you have any questions or comments, please share them below.