The multiplayer game engine
Murder is a pixel art ECS game engine
Vivid3D is an open-source 3D engine with powerful 2D UI.
An authentic Rise of The Triad Dark War source port
MIT Licensed Open Source version of Torque3D from GarageGames
A conservative source port of Wolfenstein 3-D
A conservative source port of Hexen that is identical to DOS
A conservative source port of Heretic that is identical to DOS
Urho3D Game engine
A cross-platform, open-source, pure C game engine for mobile game
Entitas is a super fast Entity Component System (ECS) Framework
Mini game engine for games104
A Tile-based Game Engine written in C# mimicing retro consoles.
Engo is an open-source 2D game engine written in Go
Retro game engine for creating games like it's 1997
A high speed C++17 Vulkan game engine
A fork of dhewm3 with an emphasis on modernisation and vanilla Doom 3
Conservative port of BOOM 2.02 to modern systems.
A fork of Chocolate Doom with small Quality of Life enhancements
Open source reimplementation of GTA San Andreas game engine in Unity
Opensource crossplatform Fallout 2 game engine writen in C++ and SDL
a UCI chess engine
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
Vivid is a modern C++ 3D engine using OpenGL4+
Go 3D Game Engine