Original sentence: GoldSrc, the engine derived from the Quake engine for Half-Life (1998) added a Direct3D support, and a skeletal framework to better render the NPCs, and also improved the NPCs AI compared to the Quake engine
Edited sentence: GoldSrc, the engine derived from the Quake engine for Half-Life (1998) added a Direct3D support, and a skeletal framework to better render the NPCs, and also improved the NPCs artificial intelligence(AI) compared to the Quake engine