I've recently found Delphi Doom, an adaptation from the original UNIX Doom C source code to Delphi. The project was finished in 2005 but the latest deploy was released on 3 March 2008 (Version: 1.0.2 build 383). I've been tinkering with it and it's been great!. It cast me back when I was young, trying to pass all the levels by killing some hideous and very nasty monsters. This Application is a WIN32 port of the famous Doom game created by ID Software. The main difference of DelphiDoom is that is written in the Pascal programming language. The source code has been translated from C to Pascal. In addition many new features have been added to to expand the old engine features and take advantage of capabilities of modern computers. Remember that you need the IWAD file just for being able to pay. The IWAD file is the file which contains all of the game data for a complete game.
Enjoy the game!.