This is for advanced software developers only: MIT App Inventor Sources. That’s the actual source code that makes App Inventor work behind the scenes – from the browser based editor to the server side support to the AI Companion. It’s all there.

MIT has made the source code for App Inventor publicly available. At a minimum, you need to be proficient in Java, Javascript, and have familiarity with various web techniques, such as JSON. Exploring this source code is not for the neophyte.

With access to the source code it is possible to host App Inventor on your own server and it is possible to develop your own App Inventor components (this also requires making a custom version of AI Companion).

Again, this is for advanced software developers.