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

[Earnie Boyd]

Quoting Jeff Eaton <jeff at viapositiva.net>:

>
> *** If you can, at any point, call debug_backtrace() and see BOTH  
> drupal functions AND functions from a non-GPL-compatible piece of  
> software, the terms of the GPL are being violated. ***
>

Then any project that uses PHP and claims to be GPL is violating the 
terms of the GPL as a rule of thumb.  PHP isn't GPL licensed[1] and its 
functions are viewable in a debug_backtrace().

[1] http://www.php.net/license/3_01.txt

Earnie