[development] Modules that integrate non-GPL PHP apps violate the GPL.

[Darren Oh]

So far this whole discussion seems to be a case of ask the wrong  
question, get the wrong answer. I have seen no evidence to suggest  
that one cannot write some code that depends on non-free software,  
release it under the GPL, and have the GPL apply to that code. What  
would be against the spirit of the GPL would be to write code that  
depends on GPL software and to release only a compatibility layer  
under the GPL, keeping the main functionality non-free. Since 1) the  
third-party apps that are being integrated do not depend on Drupal  
and 2) the module authors do not own the rights to the code in the  
third-party apps, this issue is irrelevant to the situation under  
discussion.