"Corridor 7: Alien Invasion" was a game made by Capstone Software in 1994 using the same engine used to power ID Software’s Wolfenstein 3D. Corr7TC aimed to "reimage" Corr7 on the Doom engine using the Doomsday source port, specifically a stand alone version of Doomsday v1.8.6. The aim was to add more variety to and polish the original games game play, whilst keeping the spirit of the original game. I suppose it's a sort of a remake using the original games resources. &