Wolfenstein 3D
Although id Software did not develop another "Wolfenstein" game, as their development focus shifted to "Doom" shortly after release, and has never returned to the series, multiple "Wolfenstein" titles have been produced by other companies, sometimes using game engines developed by id. The first of these newer "Wolfenstein" games was "Return to Castle Wolfenstein" in 2001, a reboot of the series, and the latest is the 2017 "".
Wolfenstein: Enemy Territory
Wolfenstein: Enemy Territory is a free and open-source multiplayer first-person shooter video game set during World War II. It was originally planned to be released as a commercial expansion pack to "Return to Castle Wolfenstein" and later as a standalone game. However, due to problems with the single-player aspect, the multiplayer portion was released on 29 May 2003 as a freeware standalone game. In January 2004, the source code for the game logic (not the game engine) was released to the benefit of its modding community.