Hexen

HeXen?: Beyond Heretic is a first person shooter game developed by Raven Software, published by ID Software, and distributed by [GT Interactive]? in 1995.

It uses a modified DOOM engine, which allows (like in Heretic) up- und down views and a network play with up to 8 players.

HeXen? introduced the "hub system" of level progression in the genre of first person shooter games.

Raven Software published the source code of HeXen? in 1999.