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

[Darren Oh]

Further simplification of the claims being made now appears possible.  
There are two:

1. You cannot use a GPL-incompatible license for an app if it calls  
functions in Drupal or in a Drupal contributed module. This claim is  
not disputed.

2. You cannot use the GPL for code that calls functions in a third- 
party app if you cannot distribute your code and the third-party app  
together as a single work using the GPL. This claim is disputed.

On Sep 7, 2007, at 6:28 AM, Thomas Barregren wrote:

> Since you already have accepted to distribute your module under GPL  
> and nothing by GPL, the license of the other program must allow its  
> derivative works to be licensed under GPL. A license which allows  
> that is said to be compatible with GPL. Examples of compatible  
> licenses include the revised BSD and the MIT licenses. If the other  
> program's license is not compatible with GPL, then you cannot  
> distribute your module. It is as simple as that.