none of us lawers here (although there are plenty of developers who tend to be) - but basically if you "distribute" your "combined" stuff in some way then yeah, you have to make your source public, according to terms of GPL. The question of what constitutes "distribution" and what exactly is "combined" stuff is a sticky point however, that noone seems to agree on and confuses a lot of "lawyers". Listen to whoever you want and they are probably going to be right and wrong at the same time, including me posting this nonsense.
...another thing to consider about law is that until this specific subject is tested in a court, all of this is up for wild interpretation - ie until someone takes this into a court room and gets a judge to make a ruling thus creating a precedent (http://en.wikipedia.org/wiki/Precedent), the decision can technically go either way. This basically means I can have a contract (license) and me and my lawyers can say all sorts of things about it, but until it gets tested in a court of law, all my talking means very little.
Does anyone know if GPL3 has been tested in a court of law?
Often, the best solution is to avoid the issue and buy a license - at least until its been tested in court (and then depending on the decision you can change your approach).
Finally, the best thing to do is ask the person whom you are entering into a contract with what they intend it to mean (the intent) - to do that, email your question to email@example.com
Last edited by gslender; 17 Aug 2008 at 9:47 PM.
Reason: added finally
Anyway i considered buying the ExtJS license - Because its just worth it. But there are also a bunch of user extensions for the JS framework which are under GPL3 (maybe those guys just didnt think about it). Which might cause trouble from their side. I dont want to run into law issues just by using a framework with extensions..
So. Considered Ext.ux under GPL3. Again an issue? :=)