Heretic is a game published in 1994 by id Software. They team up with Raven Software for this one and created medieval-fantasy-fps shooter. It became
instantly popular together with the DOOM FPS game series. This is the shareware version of the game. New versions are beeing sold by ID Software
because of great popularity of this game series.
ID software is considered a founder of FPS games. They started with Wolfenstein series followed by Doom series and Quake series. They remained active to current days with many successful titles.