Forked from RBDoom 3 BFG (Doom 3 BFG GPL) and greatly improved, Storm Engine 2 provides explosive mix of id Tech 4 and id Tech 5 technologies. Flexible modding capabilities of id Tech 4 coupled with robust and modern multithreaded rendering functionality of id Tech 5 allow real-time iteration and great performance on current hardware. Add $0.00 price tag to the mix and you get a decent indie game engine for PC platform.