Cross-Platform C++ 2D/3D game engine
An easy to use 2D HTML5 game engine written in TypeScript
Java/JavaFX/Kotlin Game Library (Engine)
Real-time physically based rendering engine for Android, iOS, and more
Naev is a 2d action/rpg space game, action, rpg and simulation
A pure Go game engine
Game engine to build text adventures.
GemRB is a portable open-source implementation of the Infinity Engine
Orx: Portable Game Engine
crossplatform multithreaded object-oriented render and audio engine
Action RPG that's easy to mod
Cross-breeding a 3D FPS with a fantasy RPG in the world of Hexen
Heros of Jin Yong 3D Remastered
SDL based generic 2D game engine
A free 3d game for PC that does not limit the player. Fight,Build,Gain
functions for 2D/3D graphics + realistic driving simulation
Delphi : VRCalc++ OOSL & + (Paged List, TextEditor, VRAstroVision ...)
Vivid3D is an open-source 3D engine with powerful 2D UI.
2D Open Source MMORPG