[ddbb]

To summarize:

Thesis integrates with Wordpress, it is not derivative from it. Same way Linux modules integrate with the Linux kernel (and many of them are closed source).

If someone is using a public/open API, and not distributing any part of the software, it means they are not based on the other.

[wazoox]

The comparison with Linux modules is problematic. Many people consider Linux proprietary modules illegal.

See for instance: http://www.oreillynet.com/linux/blog/2006/08/why_binaryonly_...

[travem]

If that API is under the GPL then isn't use of it a derivative work? If the API is a GPL implementation of a standard API, e.g. the JDBC API, then it wouldn't be a derivative work, not sure if Themes call a wordpress specific API or not though.

[dedward]

I think that's a great question, and one that could probably spawn a ton of interesting legal/logical arguments.

At what point does dynamic linking make something a derived work - and how is dynamic linking fundamentally different, than, say, a remote procedure call (or SOAP or REST or whatever) over a network? The interface is different, but the principle is the same.

Also - the GPL does state that it's okay to link against things that are "standard parts" of the target system....

[jasonlotito]

Realize you posted this before the above post was made, but apparently thesis is using Wordpress code, and not just the API.

http://drewblas.com/2010/07/15/an-analysis-of-gpled-code-in-...

[mattdawson]

Ahh. Well, nevermind my other comment in this thread. If he's ripping off WP core code, then yes, Thesis should definitely be GPL'd.