I am a Thesis developer and I am ECSTATIC that Thesis is now split-GPL licensed.

@AJ who said "Although a “split license” is kind of a joke..Doesn’t really change anything"

Quite the contrary it changes a lot. See the thing is if I customize Thesis as part of a project for a client I was in violation of their license. If I wrote a plug-in for thesis that called thesis functions I was in violation of their license.

I subscribe to the untested legal opinion that calling functions from GPL code (WP) makes a work derivative. I know plenty of people disagree with that, however I think that for a work not to be derivative (of WP) it needs to stand on it's own. Stand on it's own, as in it could run from the command line or along side Drupal or along side whatever. In other words the plug-in (or theme) would get an input, do it's thing and then return an output without calling any functions from GPL code (WP).

It's almost funny but it reminds me a lot of Apple and the iPhone. It's not the same, just similar.

No one has to develop something based on a GPL project and more than they have to develop for iOS, it's a choice. No one who chooses to develop based on a GPL project is obligated to distribute their work. If, however, they do choose to distribute it they are legally bound by copyright of the original work to the terms of the license that derivative work be distributed with the GPL.

Chris has stated many times that started by building Thesis for himself, at which point he wasn't obligated to distribute it, however when he chose to start distributing he was obligated to do it with the GPL.