5 Best Free and Open Source Game Engines in 2021

Game engines are the tools used by game designers to code and plan out a game quickly and easily without building one from the ground up. The rapid technological advancement, as well as the innovations from time to time, made it easy for the developers to create beautiful and complex games. With the help of open-source licensing, there are many good open-source game engines that can help you build games without spending money.

Free and Open Source Game Engines

Below is a list of the top 5 open-source game engines. These game engines and tools are absolutely free and available under a public license.

1. Panda3D

Panda3D is an open-source framework for rendering and developing 3D games. It uses C++ and Python programs for its creations. Thus, making the entire gaming engine be written in C++ and Python interface as its automatic wrapper generator to expose the complete functionality of the engine. Moreover, it also supports OpenGL and DirectX. This open-source engine includes various tools including but not limited to scene graph browsing and performance monitoring, animation optimizers.

Its features include a hassle-free installation and supports Windows, OS X, and Linux, full Python integration and highly optimized via C++, it comes with various OpenGL and DirectX features like GLSL, includes shadier generation, 3D pipeline, and support for Penal Audio Engine, FMOD Audio Engine and Miles Audio Engine.

2. PhyreEngine

PhyreEngine is a free-to-use game engine released in January 2012 by Sony Interactive Entertainment. This is compatible with more than just the PlayStation platforms (PlayStation 4, PlayStation 3, PlayStation VR, PlayStation Vita, PlayStation Portable) but also with Microsoft Windows (for OpenGL and DirectX 11), Nintendo Switch, Google Android, and Apple iOS thus making it successful and adopted by several game studios and now,  it has been used in over 200 published titles.


Cocos2D is an open-source game engine is maintained by the developers in Chukong Technologies. It is a development platform licensed under the MIT License. This allows the developers to build games, apps, and various interactive programs. It makes use of C++, Lau, and JavaScript for cross-platform deployments such as iOS, Android, Windows Phone, OS X, Windows, and Linux devices. Moreover, this engine is optimized for 2D graphics with OpenGL support which is packed with tons of features like coordinate systems, skeletal animation, textures, sprite sheet animation, visual effects,  tile maps, multi-resolution devices, and many more.

Its features include numerous animation options, easy GUI, supports 2D physics engine and sound effect background music and HTTP with SSL, Web Socket API, XMLHttpRequest API, and many more as network support.

4. 0 A.D.

0 A.D. is a free and open-source, cross-platform real-time strategy game that was released on July 26, 2017, under the Wildfire Games. It is written in C++, JavaScript, and XML thus making it a cross-platform that can be played using Windows, OS X, Linux, and OpenBSD. The game uses the GPLv2+ license for the game engine and CC BY-SA for the game art.

5. Id TECH 4

Id Tech 4, was initially released on August 3, 2004. It is a game engine that was developed by id Software and first used in the video game named Doom 3 (which is how they remember the game engine). It was designed by John Carmack who also created previous game engines like those for Doom and Quake which are both recognized for their significant advances in the field.

This was also used in Quake 4, Prey, Enemy Territory: Quake Wars, Wolfenstein, and Brink. Id Tech 4 features include several new graphics like normal mapping and specular highlighting and the rendering techniques used was unified lighting and shadowing, shadow volume, and Mega Texture.

Advantages of open-source game engines

Open-source game engines gave a lot of advantages in the field of game development. Examples of these advantages are the following:

  • These are better quality and more customized software,
  • Say goodbye to licensing, therefore making it absolutely free, and
  • Lower cost of hardware.

So for beginners and advanced learners, this one’s for you.

3 thoughts on “5 Best Free and Open Source Game Engines in 2021”

  1. I just wanted to point out that Godot and LibGDX are also worth mentioning, in fact Godot might be the one with the fastest growing community.

    Thanks for the article!

    Keep up the good work.


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