Stride (formerly Xenko), a free and open-source cross-platform C# game engine.

An open source library for creative expression on the web, desktop, mobile and consoles. Inspired by the classic Flash and AIR APIs.

Defold is a completely free to use game engine for development of desktop, mobile and web games.

2D game development library for Ruby and C++

Tiny fast HTML5 game engine with many features and no dependencies.

A refreshingly simple data-driven game engine built in Rust

Haxe - The Cross-Platform Toolkit

LÖVE is an awesome 2D game framework for Lua.

The Ren'Py Visual Novel Engine

JavaScript Game Engine

A modular, extendable, and easy-to-use physics engine for javascript

🚀 🌪 Super-fast 3D framework for Web Applications 🥇 & Games 🎮. Based on Three.js