Hi Guys,
With the GPL v3 licence, does the coder have to make thier own source code available for any application created using an API that is GPL licenced or do they only have to supply (or link to) the original source code of the API that they used?
This seems to be an extremely confusing area for me.
Thanks in advance. 
With the GPL v3 licence, does the coder have to make thier own source code available for any application created using an API that is GPL licenced or do they only have to supply (or link to) the original source code of the API that they used?
Thanks Sean.
Man, it is complicated. Isn't it?
I have steered clear of GPL APS's for a long time for this very reason (using native Microsoft SDK's the whole time). I don't think I'll be changing my approach any time soon, by the sounds of it.
(Upvoted your answer )
Some GPL libraries are dual-licensed with LGPL as well, which means that you don't have to release your code if you link to the library as a dynamic library. Also, there are many libraries using, in my opinion, more sane licenses like MIT/Apache/BSD.
As far as I know LGPL still requires you to release the source code of the library, it just prevents the entire program from falling under the license (and that's only if the library is linked dynamically, otherwise it's just like the GPL).
Yeah, LGPL seems fine to me. But, GPL no thanks.
I have noticed that some GPL licenced API's have clauses say that you don't need to supply your own project source. So, I guess it comes down to read 'all' of the fine print (all 100 pages of it) to be sure.
I also seem to recall something about the LGPL requireing that users can replace the LGPLed library with another version of it, including allowing people to reverse engineer your program to the extent required in order to update that library.
I wonder if one could abuse that to for example create a legal workaround for a DRM system.
I have noticed that some GPL licenced API's have clauses say that you don't need to supply your own project source. So, I guess it comes down to read 'all' of the fine print (all 100 pages of it) to be sure.
GNU's version of the standard library does this. It's released under the GPL to ensure it's not possible to modify the library and release the changes under another license, but it has that exception clause so programs using the standard library are not forcefully turned into GPL (after all, it's the standard library, not a library that's explicitly known to be under the GPL by the programmer).
I imagine this is also used by add-on libraries (i.e. libraries that the program loads on the fly that extend it). You can't use the GPL on those libraries if the program is not GPL compatible. Adding an exception clause would work around that.
I also seem to recall something about the LGPL requireing that users can replace the LGPLed library with another version of it, including allowing people to reverse engineer your program to the extent required in order to update that library.
I wonder if one could abuse that to for example create a legal workaround for a DRM system.
If I recall correctly, Nvidia abused the LGPL to connect proprietary code with GPL code.
Note that the requirement you mentioned is simpler than you think. Merely being able to swap the DLL file with another one would be enough.
Isn't that what its called as "GPL with linking exception" ?
GNU's version of the standard library does this. It's released under the GPL to ensure it's not possible to modify the library and release the changes under another license, but it has that exception clause so programs using the standard library are not forcefully turned into GPL (after all, it's the standard library, not a library that's explicitly known to be under the GPL by the programmer).
