Hazel is a simple-yet-powerful 3D game engine made by Studio Cherno and volunteers, available for use now with big plans for the future.

3D game engine with Hammer style map editor, feature light and LUA scripting support as the standard for coding

An easy to learn game engine for making 2D or 3D games. It prioritizes design and workflow for rapidly expressing ideas.

Maratis is a portable, simple and visual game development tool designed for artists and developers

3D game engine written in modern C++ and Vulkan

Nebula is an open-source and free-to-use modern C++ game engine.

Design scenes in Unity's editor. Write game logic in Lua. Export to real PlayStation 1 hardware or emulator with a single click.

Pyrite64 is a visual editor + runtime-engine to create 3D games that can run on a real N64 console or accurate emulators.

A C++20 cross-platform game framework, with emphasis on addressing pain points in existing game engines

An in-development experimental fork of Urho3D game engine

Rendercore is a proprietary 3D game engine developed in C++ by Renderon Softwares. Officially active since 2025, it is designed for building ambitious, large-scale 3D games with a strong focus on open-world environments, dynamic systems, and immersive gameplay.

Rootex is a Windows based 3D multithreaded game engine written in C++

C++ Game Engine based on Irrlicht 3D with upgraded Sound Engine, Physics Engine, and Particle Engine

Multiplatform lightweight 2D game-engine, retro-game inspired. Uses OpenGL through GLFW3. Scripted in Lua. Aiming zero run-time dependencies.

TRSE is a complete suite (IDE, compiler, programming language, resource editor) intended for developing games/demos for 8 / 16-bit line of computers, with a focus on the MOS 6502, the Motorola 68000, the (GB)Z80, the M6809 and the X86.

Experimental 3D / game engine technology partially based on the Urho3D codebase

Currently in early access. Assumed to replace Leadwerks.