That's simply untrue. First of all, you can run any program on top of Linux without licensing issues. Sure, Linux is GPL and so it much of the user land (all of

That's simply untrue. First of all, you can run any program on top of Linux without licensing issues. Sure, Linux is GPL and so it much of the user land (all of GNU being a prime example). But if your program doesn't use any of those things outside of the "common use" of those components, the license is irrelevant. However, BSD-style licenses (excluding the now-unused 4 clause BSD) allow for sublicensing, so you can also include that code inside GPL projects (sublicensed under the GPL).