Free game engine for development of desktop, mobile, and web games
Flexible level editor
Delphi Java - VRCalc++ OOSL (Script) and + (Binary Exec Distro)
The flexible game engine
The Tiny JavaScript Game Engine That Can!
Java application for creating Morphing videos
Inspecting and manipulating NBT as a file system
Edit BZFlag world maps with 3D preview
This is a Units Editor for Empire At War which will make things easy.
GPS track editor for editing tracks and planning (multiple) day tours
Custom Map File Generator for C-evo
LDraw™ editor for LEGO® style digital building instructions.
3D OpenGL dungeon game using Ada: a tribute to Narbacular Drop
A sharp, readable, vector-y version of Monocraft
Haskell game engine library for roguelike dungeon crawlers
An elegant Go board and SGF editor for a more civilized age
Advanced Minecraft auto-clicker made in C++
Searching in 3D stages
PAK file editor for Quake engine games
Open RealStrategyGameLibrary (Engine)
Solve Go problems (based on GoGrinder GoGrinder.sf.net )