Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
KlayGE is a cross-platform open source game engine
Fuel status monitor
Cross-platform 2D and 3D game engine
A distributed graph deep learning framework.
A cross-platform 2D game engine
Clojure in Unity
A fast, scalable, distributed game server engine/framework for C++
Opensource Game Studio
Character animation system for games and simulations.
A puzzle game inspired by Flowix's Einstein
Y.A.G.A.C is a free open-source platformer game
Conceptual design of Light Fixed Wing Aircraft
Planimeter Game Engine 2D - LÖVE-based game engine for Lua
Free and Open Game Programming Language for Windows and GNU/Linux
Low-Level Game Engine for Retro Platforms
Source code of the chapters of the book 3D Game Development with LWJGL
InfiFly a ML based 3D game.
Dungeon free resources (terrain & roguelike generation)
Freedoom, Heretic and Hexen
Legandary Story of the Zarakite