Yes, it's possible. Just compile it as binary. (Like done in commercial games such as Doom 3, NWN, Quake 3..)

Yes, and there is closed-source Linux software. Just make sure that you respect the licences of the libraries you use—obviously, if you use GPL-ed libraries or code in your program, you must release your source; if you use LGPL-ed libraries (such as SDL), you must link dynamically or release your sources, and so on.

(Perhaps I am belabouring the obvious, but do note that such licence restrictions do not apply to your programs simply because you use tools without including any of them in your programs—some people suffer the misconception that your code is subject to the GPL because it is compiled with GCC, written in open-source editors, and so forth.)

Quote:Original post by Whirlwind
I was left with the distinct feeling that if you didn't modifiy the source libraries, you only needed to include the source for the libraries (ie you customized and integrate parts of gcc) that you used and not any original code that uses said libraries. If you integrate any part of the GPL code into your program, you need to include your source code as well.

No, even if you only link to an unmodified GPL-ed library (or statically link to an unmodified LGPL-ed library), the pertinent licence applies; see http://www.gnu.org/licenses/gpl-faq.html#MereAggregation for a further explanation.

What you can do is use LGPL-ed libraries provided you do not link them statically.

Quote:If you use mesa as your graphics API, you just need to include sourec, etc for the distro of Mesa you use. If you integrate mesa or any part of mesa into your project, you need to include all of your source code with your project's distro.

But Mesa is not released under the GPL. In fact, it is released under a variety of licences (none of which I know much of anything about, but they are not the GPL); see the Mesa website for details.