Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
KorGE Game Engine. Multiplatform Kotlin Game Engine & Korlibs
API (C#) for simulating certain aspects of a ZX spectrum for porting.
PyCAPGE - Python Classic Adventure Point and Click Game Engine
State Management and Multiplayer Networking for Turn-Based Games
2D Game Engine
Gorgon Game Engine (GGE) is a C++ game engine that handles many tasks.