Stride (formerly Xenko), a free and open-source cross-platform C# game
Free game engine for development of desktop, mobile, and web games
Gideros Release version
Vivid3D is a C++ IDE/3D engine, with python scripting.
Urho3D Game engine
2D Game Engine
Modern 3D engine and IDE written using C# and C++.
Build Cross-platform Applications
A rudimentary 2D isometric engine
Simple animation of a journey at light speed
This is a hacking style game set in the early '80s
A lightweight, powerful editing tool for kOS Autopilot Mod on KSP.
SuperWikia: The Runtime/Realtime Environment for Codesmiths
C/C++ Programing with ALLEGRO 4.2.2 - Win32/64 - LINUX - MACOSX
Delphi-like IDE for cross-platform game development
Tournament Generator in Mono/C#/Gtk#
AMOS BASIC reimplementation in Java