Opengate is a Jumpgate remake
An open source re-implementation of RollerCoaster Tycoon 2
Sandbox video game with a powerful physics engine
Endless Sky is a sandbox-style space exploration game
Simple Beat Saber Mod Installer
Open source simulation game based on Transport Tycoon Deluxe
3D space trading and combat game
Open source clone of Theme Hospital
HTML5 Phigros chart player/simulator
Soft-body physics simulator
A planetarium software that shows a 3D simulation of the night sky
Online War system for IL-2 Sturmovik and Iron Front in ArmA 2
A free transportation simulator game
Provides self driving for ETS2/ATS.
A robocode championship manager made using JavaFx
A fast-paced free software rally racing game
Write programs in assembly that battle each other in Corewar
3D racing game with Sci-Fi elements and Track Editor
Air traffic control tower and radar simulator (solo + multi-player)
Opensource Created Custom Viewers For Virtual Worlds like SecondLife.