Java/JavaFX/Kotlin Game Library (Engine)
A free & open-source 2D sprite editor, made with the Godot Engine
RenderDoc is a stand-alone graphics debugging tool
Full featured MUD server with all the trimmings.
Modern, lightweight and efficient 2D level editor
A Strong and Easy-to-use Single View 3D Hand+Body Pose Estimator
Vivid is a modern C++ 3D engine using OpenGL4+
Explore and dissect a complete brain model in VR
Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
Cross-platform 2D and 3D game engine
XNA based game engine completely written in c#
Java 2D graphics/utility library
Pear3DEngine is a modern and modular 3D development framework
Access to Irrlicht Engine SDK from assembler, C, Python, Basic, Pascal
Game engine supporting many 3D/2D formats and graphic effects