A planetarium software that shows a 3D simulation of the night sky
Stellarium renders 3D photo-realistic skies in real time with OpenGL. It displays stars, constellations, planets, nebulae and others things like ground, landscape, atmosphere, etc.
A free transportation simulator game
Simutrans is a cross-platform simulation game where players try to successfully manage transportation systems between places by land, air, and water for passengers, mail, and goods. Planes, ships, trains, trams, trucks, buses, or monorails are at your disposal, but factories operate based on contracts and passengers can only travel to their set destinations.
A 3D simulator game where you can drive, fly, and sail
Rigs of Rods is a 3D simulator game where you can drive, fly and sail various vehicles using an accurate and unique soft-body physics engine. Since 2014, the development continued at https://github.com/RigsOfRods/rigs-of-rods UPDATE: 10/30/2016: removed opencandy installers, replaced with zip files.
WW2 U-boat simulation
SDL/OpenGL based WW2 german submarine 3d simulation, multilanguage support, multiplatform support with advanced sound and graphics. Please visit dangerdeep.sourceforge.net for any news or visit us in #dangerdeep on freenode IRC.
A UNIX/Windows/Linux remake of the DOS-game "stunts", providing modern features like openGL graphics, 3D sound and internet multiplaying. Design your own tracks, choose your opponents and try the most spectacular stunts you've ever seen.
OpenTTD is an open source clone of the Microprose game "Transport Tycoon Deluxe". For more recent versions visit our website: http://www.openttd.org
Online multiplayer Billiard/disc like game based upon Couronne
A city simulation game, a polished version of the classic LinCity game. In the game, you are required to build and maintain a city. You can win the game either by building a sustainable economy or by evacuating all citizens with spaceships.
A LGPL 3D opengl engine that uses trigonometry to make wonderful objects.
TIN is an artificial-life program running under X. TIN's are mammal lifeforms, equipped with some basic instincts and abilities, evolving in a 2D environment.
A simulated Artificial Intelligence IRC script for use with Eggdrop with many options and features and high configurability, multi-language support, grammar checker, and now with theme support! Database support is up-coming.