fheroes2 is a recreation of Heroes of Might and Magic II game engine
Magic Another Game Engine
Open Source real-time strategy game engine for early Westwood games
Embeddable unity game engine view for Flutter
3D Procedural Game Engine Using OpenGL
A simple math library for games and computer graphics
A pure Go game engine
Haskell game engine library for roguelike dungeon crawlers
GemRB is a portable open-source implementation of the Infinity Engine
Game engine supporting many 3D/2D formats and graphic effects
Orx: Portable Game Engine
Cross-platform 2D game engine (+ full OpenGL, +full OpenGL ES )
ZDoom 2.8.1 fork focusing on modernisation, performance and stability
An isometric arcade-style game of skill, puzzles and exploration
A conservative source port of Heretic that is identical to DOS
A conservative source port of Hexen that is identical to DOS
Ze Text Adventure game Builder : Create as you play !
A game engine for console based text games
A conservative source port of Wolfenstein 3-D
A Tile-based Game Engine written in C# mimicing retro consoles.
Pycraft is an open-source, OpenGL based game made in Python
Amateur 3D Game Engine
Old-school 2D game engine