Professionals and non-professionals who create or manage personal blogs, virtual stores or any other type of website in WordPress, know widely what plugins mean for administration, marketing, design and web development.
In general, once you are familiar with the WordPress environment, it’s normal to come across the term GPL, either for plugin licenses or WordPress themes, and this is what we’re going to look at today.
To begin with, WordPress is free and this is because it has been released to the world under a GPL license, thanks to its creator. But, in the case of some plugins and themes, there are GPL and Split Licenses (one part of the code is GPL and another is not).
What is a GPL?
GPL is the acronym for General Public License and this has been created and developed by the Free Software Foundation (FSF) to ensure that a software is free and its code is open to the general public.
This type of license allows end users, whether individuals or companies, to download, use, analyze, share, copy, modify and redistribute the software.
In addition this type of license is protected under a legal practice known as Copyleft, the opposite to Copyright or rights reserved for the author. This in order to ensure that the software remains free even after being modified by third parties, without a third party having the ability to appropriate the code and claim its authorship.
A GPL plugin is a free software structure which can be used, modified and distributed without any legal restrictions or limitations.
This means that once a plugin is purchased directly from the official site of its creators it can be sold, given away or used on as many sites as desired, as long as the source code remains available to its users.
In the case of the software created for WordPress under the Split License terms, an essential part (usually the PHP component and the HTML code) is kept under GPL license, since to work on the structure and make use of the WordPress libraries you need to keep part of your code open to the public.
While the other part of the software, which can be images, text, CSS styles, photographs, etc. are released under other licenses which restrict the use of these elements according to the rights that the author determines on their intellectual property.
This type of license arose in 2010 after a debate between Matt Mullenweg, creator of WordPress, and Chris Pearson, a successful software developer at the time.
Mullenweg argued that plugins and themes, being derivative and natural works of the free WordPress platform, should be regulated under the same GPL license.
Pearson argued that these elements were his creations and for that reason they should be licensed in the most convenient way for his industry.
The case was so controversial that the Freedom Law Center had to mediate the situation and defined how themes and plugins should be licensed from then on.
In this case, according to the FLC, both men were right and that is why it was determined that the software created for WordPress could be GPL and other software could have the license that the developer chose. That’s how Split License was born.
Consequently, software released under a Split License is not completely free and may have various commercial and non-commercial restrictions. As a result, the expression 100% GPL arose to refer to the software that is totally free.
A GPL plugin is an add-on that can be used by any type of user or company as long as its code remains visible and accessible so that future users can do the same.