lua dev plugin for unreal engine 4 or 5
Flax Engine, multi-platform 3D game engine
Orx: Portable Game Engine
A simulator for drones, cars and more, built on Unreal Engine
3D C++ Game Engine - yet another open source game engine
KlayGE is a cross-platform open source game engine
Easy fine console input/output for java
Open-DIS implements the IEEE DIS protocol in multiple languages.
plugin-based RPG manager in C++ and Qt5
Open Game Bootstrap