The best open source alternative to Unity is Godot Engine. If that doesn't suit you, our users have ranked more than 100 alternatives to Unity and loads of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Unity are GDevelop, Candlestick, Stride Game Engine and GABE.
Esenthel is a next gen, cross-platform C++ game engine that comes with a lighting fast, high performance game engine with advanced graphics and physics and support for multiplayer and UNLIMITED size worlds which is make the engine well suit even MMORPG titles.
Poland
EU
Multimedia JavaScript framework to create real cross-platform and hybrid game engines, games, emulators, multimedia libraries and apps.
SpainEU
Lumix Engine is an open-source 3D game design software and engine. It's written in C++ and supports several scripting languages.
Amethyst uses gfx-rs to render graphics with Vulkan or Metal. It is meant to be used for 2D and 3D, with various utilities for both types of games. It should be beginner friendly but also allow more advanced uses such as custom render passes and GLSL shaders.
Hypatia is a game engine for single player 2D action adventure games. You can use it to make a game like Legend of Zelda: Oracle of Ages and Oracle of Seasons. Hypatia is aimed at non-programmers and programmers alike.
PlayN is a cross-platform game library that allows you to create a single Java codebase that runs in HTML5, Java, Android and Flash.
United States
Your project’s smart 3D digital twin as a Service. SmartShape (formerly Minko) is a technology to develop and design rich, interactive and universal 3D applications targeting computers, web browsers and mobile platforms.
GemRB (Game Engine Made with preRendered Background) is a portable open-source reimplementation of the Infinity Engine that underpinned Baldur's Gate, Icewind Dale and Planescape: Torment. It sports a cleaner design, greater extensibility and several innovations.
GermanyEU
Heaps is a cross platform graphics engine designed for high performance games. It's designed to leverage modern GPUs that are commonly available on desktop, mobile and consoles.
FranceEU
Verus Engine is a modern, platform-agnostic 3D game engine. It is developed using C++ and HLSL. It is based on Direct3D 12 and Vulkan graphics APIs. The code is user friendly and well optimized.
EstoniaEU
The G3D Innovation Engine is a commercial-grade C++ 3D engine available as Open Source (BSD License). It is used in commercial games, research papers, military simulators, and university courses. G3D supports hardware accelerated real-time rendering, off-line rendering like ray...
United States
