Unreal’s licencing has changed and PhysX source code going into UE source tree.
Unity’s licencing has changed as well.
Valve is following with licencing change (no details yet) for the Source 2 engine
GCC might get SPIR support.
Enlightment demo: https://www.youtube.com/watch?v=TLPedv_h8vY
Unreal kite demo: https://www.youtube.com/watch?v=nwuFd5uK_xQ