Nau Engine is a free open-source game engine that's designed to be versatile and accessible to everyone.
It's free: no limitations, royalties or other fees apply. Nau Engine will always be free for any purpose, including commercial use. It's open: the entire source code is stored in a GIT repository. Anyone is able to use it for educational purposes or work with it as they wish. It's open-source: anyone has the opportunity to participate in developing the engine without restrictions, creating forks and add-ons based on it.