fheroes2 is a recreation of Heroes of Might and Magic II game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF
Solar2D Game Engine main repository (ex Corona SDK)
Magic Another Game Engine
Open Source real-time strategy game engine for early Westwood games
The Open Toolkit library is a fast, low-level C# wrapper for OpenGL
A .NET ascii/ansi console engine written in C# for MonoGame and XNA
Svelto ECS C# Entity Component System
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Animation Compression Library
A game framework written with osu! in mind.
Embeddable unity game engine view for Flutter
Opensource crossplatform Fallout 2 game engine writen in C++ and SDL
Game engine to build text adventures.
Javascript library for making tile based games
RTSish Game Engine
Free and Open Game Programming Language for Windows and GNU/Linux
Game engine for playing tomb raider 1 - 5 levels.
A space race game in the style of A Dark Room
Community-driven game engine
Multi-platform game engine similar to old Megaman with a stage editor
Paintown is a 2d fighting game engine.