ergophobe - 8:57 pm on Jul 21, 2010 (gmt 0) [edited by: ergophobe at 9:20 pm (utc) on Oct 1, 2010]
If you start from documentation of the interface to Wordpress and create files with new code, then the GPL does not apply unless you copied GPL'ed code from the documentation.
Actually, that's the question under debate. That is not the position of the Free Software Foundation, Gnu or the people at Wordpress. Quite simply, if your code doesn't run without the GPL application it depends on, it must be GPL. See the stuff I quoted above.
So Thesis definitely fails the one test (it did copy GPLed code) and it fails the second test (it won't run without Wordpress), but the second test has yet to have a definitive decision in a court of law, so precedent is still lacking.
Koen, I think it does and it speaks to the previous post too. If Wordpress folks had wanted people to be able to create themes and plugins not under the GPL, they would have chosen a license more like the PHP or BSD license.
This has been handled in a variety of ways.
The GPL itself has a GCC Runtime Exception
Java uses the LGPL, which basically is designed for exactly the situation you describe.
Meanwhile, as of version 4, PHP gave up dual licensing and trying to maintain GPL compatibiity and now use the PHP License
The PHP license is a BSD-style license which does not have the "copyleft" restrictions associated with GPL.
Q. Why is PHP 4 not dual-licensed under the GNU General Public License (GPL) like PHP 3 was?
A. GPL enforces many restrictions on what can and cannot be done with the licensed code. The PHP developers decided to release PHP under a much more loose license (Apache-style), to help PHP become as popular as possible.
[edited by: ergophobe at 9:20 pm (utc) on Oct 1, 2010]