FreeDoom is a free open source FPS Games and a clone version of DOOM (free Doom Game)
Originally Released: 1993
Latest Release: Oct 2019 Freedoom 0.12.1
License: GNU GPL
Developer : Freedom Project
This is a free open source first person shooter (FPS) under continuous development. The project distributes three IWAD files: the single-player campaigns named Freedoom: Phase 1 and Phase 2, and FreeDM, which contains a collection of deathmatch levels.
The project presents itself as complementary to the free source code of the Doom engine released by id Software in 1997 under the GPL license. It allows custom levels and other customizations designed for Doom or Doom II (e.g. PWAD files) to be used with it.
The project aims to create a complete free content game based on the Doom engine. Combined with the engine, It is also compatible with original game modifications (“mods”) made for Doom games, by Doom fans and artists over the decades.
It is available in two versions, the first of which is a single-player focused game, split in two parts, each of which is compatible with different versions of the classic Doom franchise from id Software.
The second is a multiplayer-focused experience for the popular “deathmatch” game mode.
Minimum System Requirements:
Processor: 66 MHz
Memory: 8 MB
Graphics: 32-bit video card
Hard Drive: 100 MB free space
Screenshots
technically freedoom is just a stock map and asset set that replaces the need to have the commercial doom 1 and doom 2 wads to run mods. Also should notate in the article that it requires a source port (foss doom engine). GZDOOM for all the bells and whistles, Crispy doom for the old-school feel but with some modern features, and chocolate doom for the old-school DOS purists.