Hey Everyone, I'm writing a 3D Modeler/Animation tool which is targeted towards the hobbyist game development community (think of somewhere between Milkshape and 3dsmax). The application itself will eventually be commercial and closed source, but the PluginSDK will be released under a BSD-style license. Now my big question is, when I ship the application I'd like to include GPL'd code as plugins (i.e. some Quake 2 export/import dlls I wrote from the Quake 2 code base). I will obviously give all the source code and appropriate licensing details in the application plugin/source directories, but I want to know if this is enough to satisfy the licensing conditions without having to give away my base application code? The application simply recurses the plugins sub-directory for all *.dll files then attempts to load them so there is no dependency on the GPL'd code for it to run. Any thoughts or advice would be great. Thanks!

That'd probably be fine. To the extent that the GPLed code and the non-GPLed code would have any code sharing, it would be entirely one-way: headers from the BSD codebase being used in a GPL codebase. The GPL's "mere aggregation" clause would allow it.

One more thing I just want to throw out there. The headers in the PluginSDK (BSD license) contain the function pointer prototypes that are passed from the application (closed source) to the Plugins (GPL license code). The GPL code can run these function pointers to add new data/functionality to the modeller (i.e. create model, add triangle, etc...). Is this an issue at all?

It sounds no different than creating a gnu-licensed plugin for any other commercial product. You can publicly release the interface without infecting your own application with the GPL license.

You should probably (just for clarity) market them as distinct elements.

Example: Here is my commercial tool, and it supports plugins. Next, here are several plugins. Some of these plugins are distributed under the GPL.

Doing it this way makes it obvious that your own tool does not rely on its own GPL-licensed bits, and ensures that the gpl-licensed bits are completely independent from everything else.

IANAL. That said, if you release those plugins, it could be construed as being part of the program, and as such it could be argued that you could be in violation.

I'll ask a lawyer friend of mine for corroboration on that and see what he says.