NunuStudio is an open source 3D game engine that utilizes the Three.js framework (tutorial-lite available here) and is free to use. It includes a comprehensive editor that can be accessed locally or remotely via web browser.
NunuStudio boasts several features, including:
- The ability for designers and web developers to easily create 3D experiences for the web
- Direct web compatibility, as well as the option to export as a desktop application through nwjs.io
- A fully featured visual editor that supports multiple file formats
- Open source and completely free to use for personal and commercial purposes
- Visual scene editor, code editor, and visual tools for editing textures, materials, and particle emitters
- A powerful scripting API that enables the creation of complex applications using JavaScript or Python
- A fully featured web-based version of the editor available on the project page
- Compatibility with Firefox, Chrome, and Microsoft Edge, as well as mobile browsers.