A mature cross platform graphics engine designed for high performance games. It was used in major titles like Dead Cells, Dune Spice Wars, Northgard and Wartales.

WASM-4 is a low-level fantasy game console for building small games with WebAssembly

A web framework for building virtual reality experiences

Urho3D is a free lightweight, cross-platform 2D and 3D game engine

An interactive fiction engine for web games, powered by Inkle's ink

A tool to help you create new puzzle games you can play on an NES

A simple Lua framework for rapidly building VR experiences

Software library and tools for making the Tramway Drifting and Dungeon Exploration Simulator 2022 and similar applications. Similar to Quake, GoldSrc or Source engines, but it uses polygonal soup instead of BSPs and supports level streaming.

Inform is a programming language for creating interactive fiction, using natural language syntax

A powerful game development platform to create world-class entertainment experiences

Hotham is an attempt to create a lightweight, high performance game engine for standalone VR headsets, like the Oculus Quest 2

The Irrlicht Engine is an open source realtime 3D engine written in C++

A hand-crafted 2D game library in Go

Playscii is an open-source ASCII art and game creation program with Python scripting.

A minimalist Kotlin Multiplaform Game Engine

nCine is a cross-platform 2D game framework written in C++ with an emphasis on performance, but it is also scriptable in Lua for more flexibility. You can use it to create your games and tools or to learn and experiment with its source code.

2D game engine written in Haxe, with a block based visual scripting system inspired by Scratch

Lost Astronaut's Game Creation Framework: A massive 1800+ class 1400 file extravaganza of OpenGL, WinAPI, OpenAL and many other features, written in Visual Studio for over a decade! The project seeks to port to a Linux/Winux environment from Visual Studio.

And engine to make simulations of any kind, ranging from simple prototypes to professional 2D and 3D games, simple physics or graphics demonstrations to robust, realistic simulations

Echo is a game engine which uses many industry-standards for game development

2D Game Engine with Lua Scripting made on top of SFML

Data-driven game engine written in Rust

A combination of an editor and a simple JavaScript library to create game without the cumbersome aspects of HTML5 development

A LÖVE-based game engine designed for multiplayer-first game experiences

A multi-platform framework for building 2d games, interactive books, demos and other graphical applications

An open-source fantasy computer using Lua.

A cross platform game engine that can be used to make simulations of any kind, ranging from simple prototypes to professional 2D and 3D games, simple physics or graphics demonstrations to robust, realistic simulations.

Free and opensource 2D+3D game making for indies

Limon is a multi platform 3D game engine mainly focusing on first person games. Focus of its development is ease of use and ease of study.

The successor version of Kirikiri 2, allows you to create 2D games and applications, and is used in many commercial adventure/novel games