I'd like to incorporate GPL-covered software in my proprietary system. Can I do this?
If you proprietary software is "stand-alone", i.e. if it doesn't matter if XOOPS is there or not, then you can do it. Otherwise see:
1) If a library is released under the GPL (not the LGPL), does that mean that any program which uses it has to be under the GPL or a GPL-compatible license?
2) You have a GPL'ed program that I'd like to link with my code to build a proprietary program. Does the fact that I link with your program mean I have to GPL my program?
There is also an interesting post here, where it's being said that:
Quote:
While the GPL only covers distribution, they consider it a GPL violation to *distribute software that is intended to be used in violation of the GPL*. In other words, distributing a proprietary commercial piece of software that relies on GPL libraries, and telling people, 'We can't put X into our program, but you can to make it work...' is creating a GPL-derived program just as much as rolling the GPL'd libraries in and then distributing.
So, while no one is going to root around your server seeing if you've called include() on something non-GPL, distributing that middle component is, in the FSF's eyes, an attempt to circumvent the GPL.
The same is valid for so called "bridges" between a GPL program (e.g. XOOPS) and a proprietary program. Using a bridge to call functions from XOOPS would be a violation of GPL:
Quote:
The issue ultimately lies in HOW the software is integrated. 'loosely coupled' mechanisms like REST, most XMLRPC stuff, direct manipulation of databases without calling APIs, etc., are generally OK because they are 'standard mechanisms that separate porgrams use to communicate with each other.' No matter what we call it, most bridge modules ultimately work out to: "Program 2 is sucked into the execution chain of some Drupal code, via a bridge module."