Open Source C Game Engines for BSD

QuakeSpasm is a *Nix friendly Quake Engine based on the SDL port of the popular FitzQuake. It includes some new features, important fixes, and aims for portability and 64 bit correctness.

A portable game engine for classic first person shooters such as DOOM, Heretic and Hexen. Lets you enjoy the original games using modern technology, including high-resolution OpenGL graphics, 3D models, and dynamic lighting effects.

3D game framework in C, with Luajit and Python bindings now.

Aleph One is the open source continuation of Bungie's Marathon 2 FPS game engine. Aleph One plays Marathon, Marathon 2, Marathon Infinity, and 3rd-party content on a wide array of platforms, with (optional) OpenGL rendering, Internet play, Lua scripting, and more.

Smokin' Guns is a GPLv2 licensed first person Western style shooter based on the Quake 3 engine (Id Tech 3) developed by a loosely knit team of developers and artists. This project represents the game engine.

Haxima is an Ultima-like game engine (2D tile graphics) with combat, magic, NPC AI, an embedded scripting language, and in-game editing.

OpenMoHAA is a game engine that is compatible with Medal of Honor: Allied Assault media and network protocol, based on the ioquake3 project.

RetroGear is a generic 2D game engine, designed for the simple and fast retro games development, like those of the 80s. The project aims to create generic components for rapid development of 2D games, based on the most common practices of game programming and design known, giving in the hands of the programmer, standard components and easy to integrate with their own projects. Some of the features offered by this game engine are: A basic but pratical game states management (screen titles, pre-game, game, game over, etc ...) Management of 2D maps, with practical and useful tools for managing graphics, scrolling and collisions. Functions for handling graphics at high and low level, with the addition of functionality to the management of animations of the game entities, in a fully automatic manner. Management of basic audio Scope of game dynamics and designed to be used in a variety of game types, so easy and fast, thanks to the dedicated functionality.

Pipmak is a cross-platform game engine and authoring environment for point-and-click adventure games in the style of the Myst series. It supports panoramic nodes and uses Lua for scripting.

OliveChess is a simple chess engine compatible with modern chess interfaces such as ChessBase products, Arena and XBoard/Winboard. The engine supports UCI and XBoard protocols. Note: in order to use it as an xboard engine you may need Polyglot tool to be installed first

JavaScript game engine focused on 2D multi-player (networked) games. The idea is to provide a tool for learning by writing computer games. EGachine is based upon a extensible JavaScript shell (EJS) and modules providing functionality for writing games.

Create C/C++ 3D games easily! Game engine including higher-level functions and highest-level that are little less than working games! Include an audio system, an thread system, events, entities, physics, etc. This engine is written in C and C++. But can be used from both languages. It is powered by glib, Irrlicht engine, OpenAL, ODE, Ogg vorbis, etc

IRE is a tile-based Computer Role-Playing Game engine based on Ultima 6, but with an emphasis on customisation and cross-platform support. Everything is controlled using scripts.

MyWorld is an open virtual reality and game engine. It is written and usable in C/C++. It has own abstract layers for Graphics and Physics. Actually we use Irrlicht for 3D-Rendering and GUI, and ODE for Physics. It is smart, powerful and easy to extend.

Orx is a portable, lightweight, plugin-based, data-driven and extremely easy to use 2D-oriented game engine. As orx is data driven, it allows users to create games with a small number of lines of code and reduces drastically the development time.

Action/RPG Game Engine. Overall game engine is to be open source, but not the art assets.

A platform independent 2d game programming framework for c/c++ programmers with least possible dependencies for easy porting and with focus on easy api calls and the requirement of commercial programmers

Terra Tenebrae is a free (as freedom) multi-Players RPG game engine based on client/server technology. The assets used are in licenses CC0, CC-by, CC-by-sa or GPL.

WFIRE is a low-level game engine which provides a portable library allowing for writing video games for multiple classic targets. Originally written for a game called the Crypts of Eldor, WFIRE aims to provide compatibility with a number of constrained environments, such as DOS and the Amiga. It also aims for "new-retro" computers such as the Commander X16 and the Neon816. Of course, modern operating environments such as Windows NT and GNU/Linux are also planned. WFIRE is meant to reduce the effort of writing your own game engine by providing a common framework for functions such as rendering, sound output, and display management.