Complex sentence: As for the PC, over 50 different "Doom" source ports have been developed--many of them still under active development--that add new features such as OpenGL rendering and scripting, allowing WADs to alter the gameplay more radically.
Split into simpler sentences: As for the PC, over 50 different "Doom" source ports have been developed. New features such as OpenGL rendering and scripting allow WADs to alter the gameplay more radically.