Minecraft map editor and mod
Flexible level editor
An OpenGL RTS game engine written in C
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Custom Map File Generator for C-evo
MIT Licensed Open Source version of Torque3D from GarageGames
Modern 3D engine and IDE written using C# and C++.
MCEdit: World Editor for Minecraft
IRB is a game creation toolkit
Pear3DEngine is a modern and modular 3D development framework
A 2D Side Scrolling Platformer Game
1st 3D game engine built in C# for .NET, Visual3D Engine's predecessor
SmartMap is an easy desktop random world creator.