Comment by williamstein

CoCalc is a collaborative replacement of Jupyter notebooks. It's a top-to-bottom re-implementation of the entire Jupyter stack designed specifically for realtime collaboration. You can use it via our hosted offering (https://cocalc.com), or install it on prem via https://github.com/sagemathinc/cocalc-docker.

We released the our collaborative Jupyter notebook in 2014 as a plugin to Jupyter classic. We then iterated on what we learned over the years, completely rewriting everything multiple times, including the entire realtime collaboration stack. Cocalc's Jupyter support is pretty mature and battle tested at this point, and also includes a TimeTravel slider that lets you view all past versions of a Jupyter notebook and integrated chat.

I was a college professor (at Univ of Washington), I started a company around this in 2015, so CoCalc has soo far been mainly aimed at serving the needs of academics teaching courses. It's been increasingly popular lately, e.g., in the last month over a half million distinct Jupyter notebooks were edited on https://cocalc.com. Of course, many of these notebooks are homework problems. Anyway, our company is doing very well, and we hope it will eventually be a "10M startup opportunity". :-)