The IDE is powered by ACE editor, but you have a terminal that is 100% capable of running emacs / vim, but since the terminals are shared you can't have multiple cursors like you can in the editor.
But you can also enable vim mode from the editor settings if that's your jam.
I would like to see screenshots and a list of supported languages/frameworks.
Also, the homepage says "Run it, commit it, and move on". Do you have native support for git? (And if you do, is it just github, or do you support gitlab, bitbucket, etc?)
The containers are powered by docker, and all of our pre-built docker images come with git pre-installed. You have root on the machines so you can use a package manager to install any packages you feel are missing (the pre-built docker images are ubuntu so you could run `sudo apt-get install subversion` for instance).
Since we're not opinionated you should be able to pull/push from any git server.
But you can also enable vim mode from the editor settings if that's your jam.