[rickjames28]

You have to license any code that links with GPL code under the GPL. This does not prevent you from dual-licensing your own portion of the code base, or shipping non-GPL, non-linked code as part of the same product (Although in the case of things like DLL plugins it gets a bit hazy)

Actually, that's a common, but wrong interpretation. The whole work becomes GPL, but the code that links to GPL code doesn't have to be GPL.

[foobarbazqux]

It has to be "GPL-compatible" though, which means whoever you give it to can convert it to the GPL by adding the extra conditions of the GPL to it.