The source code to VVVVVV
Ct.js is a desktop game engine that makes learning programming fun
Free game engine for development of desktop, mobile, and web games
3D Game engine with editor
A sharp, readable, vector-y version of Monocraft
Stride (formerly Xenko), a free and open-source cross-platform C# game
Games for tomorrow's programmers
Action-adventure game originally released in 2013
KorGE Game Engine. Multiplatform Kotlin Game Engine & Korlibs
The Tiny JavaScript Game Engine That Can!
The flexible game engine
World Class Leader Board Editor.
Descent 3 by Outrage Entertainment
Delphi Java - VRCalc++ OOSL (Script) and + (Binary Exec Distro)
Retro style, multi-platform soccer game
Europa Universalis 4 save game editor
A free 3d game for PC that does not limit the player. Fight,Build,Gain
A cross-platform, open-source, pure C game engine for mobile game
An elegant Go board and SGF editor for a more civilized age
Modern 3D engine and IDE written using C# and C++.
Solve Go problems (based on GoGrinder GoGrinder.sf.net )
Web powered cross-platform 3D, WebXR game engine
A fantasy RPG.
Tools using the s3pi library and other related works