3D Realms (legal name Apogee Software, Ltd.) is an American video game publisher and video game developer based in Garland, Texas, United States, established in 1987. It is best known for popularizing the shareware distribution model and as the creator of franchises on the PC such as Duke Nukem, and also the publisher of other franchises such as Commander Keen and Wolfenstein 3D. More: en.wikipedia.org.