Actually Colab was created as a University of Illinois research project to prove the feasibiliy of creating a real time collaborative Jupyter editor by two undergrads over the course of a semester, most notable for winning HackIllinois 2021.
It is no longer maintained or operating, has no users, and makes no money. It was free, open source, never open to the public, and has had no servers online these days. However, we do hope that the code we wrote helps someone.
We want to make it extremely clear that there is ZERO relationship between this project and Google or Google Colab. They are not sponsoring it, partnering with it, or involved in any way. Though we do hope they add real time collaboration to their product :)