What Text Editor and Diff Viewer does Meteor Forum use?

I am curious what is the Rich Text Editor that Meteor Forum application uses?
The most interesting feature is automatic diffing view of posts history changes as seen in attached picture here under. I would like to use this diff-viewer in my project.
Is this own code or some Atmospehre package or NPM library?

The meteor forum isn’t build on meteor, not even on node. You can find it here: https://www.discourse.org/


Interesting. Thank you very much.

Get the chome app “Wappalyzer” to see what any site uses in its stack.

this is amazing. Thanks