Agar (engine) - A high-level graphical application framework used by 2D and 3D computer games
    * Axiom Engine - A fork containing the core of the OGRE graphics engine
    * Haaf's Game Engine - A 2D Hardware Accelerated Game Engine
    * Boom - A port of the Doom source code by TeamTNT
    * Build engine - A First person shooter engine
    * Cadabra 3D Engine - 3D engine for easy game development
    * Catmother - A BSD-licensed engine from a company that open-sourced its code when it closed the business.
    * CheapHack - An outdated TomazQuake derived engine
    * Crystal Entity Layer - An extension of the Crystal Space 3D Engine
    * Crystal Space - A general framework for developing 3D applications
    * Cube - Powers the computer game of the same name
    * DarkPlaces - One of the most advanced free software Quake engines
    * Delta3d - Integrates other well-known free software projects into an easy-to-use API, originally developed by the U.S. Navy
    * DGD - An object-oriented programmable MUD engine
    * Doom engine - The now free software engine originally used for Doom and Doom II
    * Elysium Source - A 2D online game engine made with VB6
    * Eternity Engine - A source port of the Doom engine
    * Exult - A free software reimplementation of the Ultima VII game engine
    * FIFE - A free software 2D ISO engine supporting the assets of Fallout 1 & 2
    * Game Blender - A sub-application of Blender for creating games
    * Game Maker - Object-oriented game development software with drag-and-drop interface and its own scripting language
    * GQ - A Quake engine that adds features from TomazQuake and DarkPlaces
    * GZDoom - A source port of the Doom engine based on ZDoom
    * Genesis3D - A real-time 3D engine for Windows
    * GemRB - A free software implementation of the Infinity Engine
    * Irrlicht Engine - A cross-platform engine known for its speed and 3D engine capabilities
    * Jogre - a Java based client/server game engine and API for online real time games such as chess, checkers, etc.
    * MRPGe - Visual Basic 2D RPG game engine, with built-in scripting capabilities. Very customizable, in early development stages.
    * Multiverse Network - an MMOG platform, including server, client, and tools. (Free for development and use--revenue sharing upon commercial deployment).
    * Nebula Device - A realtime 3D game engine developed by German game studio Radon Labs.
    * OctLight - A Java game engine that uses scene-graph and renders on top of Lightweight Java Game Library (LWJGL) using OpenGL
    * OGE - The Open Game Engine is an open source library combining the components used to make games.
    * OGRE Engine - A very popular object-oriented graphics rendering engine. Also called OGRE3D
    * Pentagram - A project to create a game engine that is capable of running Ultima VIII: Pagan
    * PlayerWorlds - The simplest, most used 2D Online EPG engine available today
    * PLIB - A game engine - includes 3D, Audio, Music, GUI, Window manager and is portable Linux/Windows/MacOSX.
    * ProQuake - A modified Quake engine
    * Quake II engine - The original free software Quake II engine from Id Software
    * Quake III engine - The original free software Quake III engine from Id Software
    * RealmForge - An open-source game engine for the Microsoft .NET Framework, predecessor to Visual3D.NET
    * Sauerbraten - A upgraded engine forked from the Cube engine
    * Sonic Robo Blast 2 - A heavily modified Doom Legacy engine for a 3D platform fan-fiction game of the same name.
    * Stratagus - A cross-platform real time strategy game engine
    * Telejano - a modified Quake engine
    * Tenebrae - One of many Quake engine clones
    * vbGORE - Open-source online RPG engine in Visual Basic 6 (2d via 3d hybrid engine).
    * Well of Souls - A 2D engine with scripting in QUEST and a visual world editor.
    * Yake - a component-based, object-oriented, partially generic engine written in C++
    * Arcane Engine - Designed by Wolfpack Studios for Shadowbane
    * Aurora Engine - For Role-playing games
    * Baja Engine - Professional quality engine used for the game The Lost Mansion.
    * BRender - A real-time 3D graphics engine for computer games, simulators and graphic tools
    * C4 Engine - An emerging next-generation computer game engine created by Eric Lengyel
    * Coldstone game engine - an old game creation suite for Macintosh/Windows to create role-playing or adventure-style games
    * CryENGINE, CryENGINE2 - The game engine used for the first-person shooter computer game Far Cry. CryEngine 2 is a new generation engine developed by Crytek to create the unreleased FPS game Crysis.
    * Dagor Engine 3 - A high-tech cross-platform game engine (3D, physics, game logic) with rich toolset for content development
    * Dark engine - An outdated engine used for the Looking Glass Studios games
    * Doom 3 engine - Used by the games Doom 3, Quake 4, Prey and Quake Wars
    * Earth-4 Engine - The graphics engine used in Earth 2160
    * Electron engine - Currently in development by Obsidian Entertainment for their game Neverwinter Nights 2, based on the Aurora engine
    * Explorations - 2d MMO creator
    * Gamebryo - A cross-platform 3D computer graphics engine coded in C++
    * GeoMod - An engine developed by Volition Inc. in 2001, and used in Red Faction, and with improvements, in Red Faction 2. This engine allows realtime terrain destruction to a certain level.
    * GoldSrc - The heavily modified Quake engine that powers Half-Life
    * Havok (software)[1] - Very High-tech cross platform (PC, PS3, Xbox 360 etc) middleware Engine.
    * IMUSE - Specifically designed to synchronize music with visual action
    * INSANE - Used in LucasArts games
    * Infinity Engine - Allows the creation of isometric computer role-playing games
    * Jedi - A game engine developed by LucasArts for Star Wars: Dark Forces and Outlaws
    * KjAPI - A C++ technology to create games and 3D applications for PC computers
    * Lithtech - A competing alternative to the Quake, and Unreal engines.
    * Lithtech Juipter Ex - A new generation Lithtech engine developed by Monolith to create the game F.E.A.R.
    * M.U.G.E.N - A 2D fighting game engine
    * Medusa (game engine) - A C++ 3D game engine developed by Palestar and used in the DarkSpace MMO. It features distributed world simulation, single tool version control and asset realisation, cross-platform compatibility and an integrated client/server network system.
    * Multiverse Network - an MMOG platform, including server, client, and tools. (Free for development and use--revenue sharing upon commercial deployment).
    * Odyssey Engine - Used to create three dimensional computer role-playing games, used Star Wars: Knights of the Old Republic
    * ORE - Online RPG Engine
    * Quest3D - www.quest3d.com
    * Power Render - A general purpose software development kit for games and 3D visualization
    * RAGE - A game engine created by Rockstar Games use it to power their upcoming video games on the Xbox 360 and PlayStation 3
    * Reality Engine - 3D game engine by Artificial Studios
    * RelentENGINE - A next-generation FPS engine supporting massive destroyable city environments and realistic vehicle control, makes extensive use of shader model 3.
    * RenderWare - A very popular 3D API and graphics rendering engine
    * Retribution Engine - A game engine to make first person shooter games
    * Revolution3D - A 3D graphics engine developed by X-Dream Project
    * RPG Maker XP - A 2D engine to make top-down and isometric-style role-playing games for Windows.
    * SAGE engine - Used to create real-time strategy games
    * SCUMM engine - Used in LucasArts graphical adventure games
    * Shark 3D - A middleware from Spinor for computer, video games and realtime 3D applications
    * Silent Storm engine - A turn-based strategy game engine
    * Sith - A game engine developed by Lucasarts for Jedi Knight: Dark Forces II
    * Source engine - a popular engine used in Half-Life 2 and other games.
    * Torque Game Engine - A modified version of a 3D computer game engine originally developed by Dynamix for the 2001 FPS Tribes 2
    * TOSHI - A fourth generation cross platform game engine designed by Blue Tongue Entertainment
    * Truevision3d - A 3D game engine using the DirectX API
    * Unigine - Cross-platform middleware with great graphics
    * Unity (game engine) - An easy to use 3d game engine
    * Unreal engine - One of the most popular game engines for action games
    * Vengeance engine - A video game engine based on the Unreal Engine 2/2.5
    * Vicious Engine - Available for Microsoft Windows, Sony PlayStation 2, Microsoft Xbox, and Sony PlayStation Portable
    * 3DGame Studio - www.3dgamestudio.com
    * Vision Game Engine - www.trinigy.de
    * Visual3D.NET - 3D platform and visual development environment built upon Microsoft .NET 2.0 and XNA Framework for developing for PC, Xbox 360, and Windows Mobile devices using C#, Visual Basic, J# (Java), C++.NET, JScript.NET, IronPython, and visual scripting. (www.visual3d.net)
    * Virtools - www.virtools.com
    * White Engine - Square-Enix's proprietary seventh generation game engine to be used for their PS3 projects. Designed to be able to render pre-rednered CGI quality graphics in real-time.
    * Zero - 3D game engine used in Star Wars: The Clone Wars, Star Wars: Battlefront, and Star Wars: Battlefront II
    * Maz 3D Game Engine - Designed by Students C++ & OpenGL