GNU General Public License (version 2 or later)
Image Source: https://stallman.org
why should I care?
Did you know that all your WordPress code is GPL too?
That's a good thing! Right?
“(GPL) is a cancer that attaches itself in an intellectual property sense to everything it touches.”
- Steve Ballmer
Open Source is awesome!
WordPress is freely available to anyone to use for any purpose, and without permission.
Lots of people, even huge companies rely on WordPress. Everyone benefits.
You can create your own plugins and themes to do anything you want.
Yes,
You are allowed to sell GPL themes and plugins.
You can't make money with GPL code.
These guys seem to be doing pretty well
You don't have to pay money for GPL plugins or themes
The Premium Plugin / Theme model:
GPL means Free as in Freedom
Not as in Free Beer
Premium Plugins and Themes aren't GPL
Yes, They are.
"PHP in WordPress themes must be GPL, artwork and CSS may be but are not required."
- Matt Mullenweg
Plugins, by definition, use WordPress GPL codebase.
They are considered derivatives.
So are themes.
Open Source software like WordPress is developed by Hobbyists for free
2011 | 2012 | 2013 | 2014 | |
---|---|---|---|---|
Investments | $398M | $669M | $920M | $1.3B |
Average Deal | $8M | $14M | $18M | $33.9M |
Num. deals | 49 | 49 | 51 | 39 |
Source: 2015 Future of Open Source Survey
Would you do it for free?
Open Source and GPL are what make WordPress so great!