scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Cross-platform game engine in Rust
High performance UI layout library in C
Open source library for creative expression on the web, desktop, etc.
A .NET ascii/ansi console engine written in C# for MonoGame and XNA
The HTML5 Creation Engine
A pure Go game engine
Powerful, mature open-source cross-platform game engine for Python
Game engine supporting many 3D/2D formats and graphic effects
Rust library to create a Good Game Easily
2D Game Engine with Lua Scripting made on top of SFML
Low-Level Game Engine for Retro Platforms
Portable game engine with main focus on point-and-click adventures
Web powered cross-platform 3D, WebXR game engine
2D Game Engine, based on OpenGL and focused on Isometric Games
Demonstrating the features of jMonkeyEngine 3.
Game engine supporting many 3D/2D formats and graphic effects