Needle Engine is a web-based runtime for 3D apps. It runs on your machine for development, and can be deployed anywhere. It is flexible, extensible and has built-in support for collaboration and XR! It uses three.js and Typescript to implement a run time game engine that goes a long way toward implementing most of the functionality of the Unity runtime engine.
Needle Tools for Unity bridges the Unity Editor and the web runtime. It helps you to export your assets, animations, lightmaps and 3D scene graph to the web and it helps you bring your TypeScript and three.js based code into Unity so it can be triggered by Unity events and configured in the Unity inspector like built in Unity components. It is built around the glTF standard for 3D assets and uses the gLTF extension mechanism to store the properties you see in the unity inspector so they can be used at runtime by the Needle Engine.
Together, they enable incredible iteration speeds and help you to bring your content to the web. Some have called it the "Missing Link" between artist-friendly workflows and modern web development!
Visit the docs at engine.needle.tools/docs