Multi-platform 2D and 3D game engine
Powerful, mature open-source cross-platform game engine for Python
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Modified source engine (2017) developed by valve and leaked in 2020
Mini game engine for games104
A high speed C++17 Vulkan game engine
A 2D game engine and level editor
KlayGE is a cross-platform open source game engine
A fast, scalable, distributed game server engine/framework for C++
Open-source, cross-platform, C++ game engine for creating 2D/3D games