DjDoom is a reference implementation for the original Doom game engine that I have been working on for a little while. The purpose of this project is to build a playable Doom engine from the original Linux source code with minimal changes necessary to build and run in a Windows environment. This was created as a learning tool for me and I'm publishing this so it can be a learning tool for others. It is intended that this be a base for others to build and expand on.
I deliberately chose to not use any third party libraries to handle sound, input and graphics and instead used only what is usually available on a typical Windows platform. I use DirectX 8 for graphics and input (including keyboard, mouse and joystick). The sound utilities took the most effort to write since Windows does not make it easy to play MIDI music and sound effects. Learning to use the Windows Multimedia APIs to play MIDI resulted in a few other articles on this blog.
The game engine is built on Windows using MinGW. You will also need the DirectX 8 SDK. Newer DirectX no longer includes Direct Draw and won't work for this code. DirectX 8 SDK comes with Windows Game Programming for Dummies, Second Edition which is where I got it from. The original DooM code was released by iD Software under the GPL. The additions I made are released under a more permissive MIT license.