":F Normal CTF for stupid" at
http://akvariumok.uw.hu/ has one map in its cycle (Face.pk3) which uses skybox stolen from Quake II. Its readme also states that all textures are from UT.
I thought I was seeing things at first, but no, it was Stroggos filing the sky. Such a *blatant* theft. FRom id software, no less.