This is "Vim Online", a vim editor in browser. It's an online vim editor that allows you can install your vimrc, and this app will remember your vimrc between visits to a vim editor online.
While those projects did a great job getting started on an online vim editor, there are still many missing pieces. The most important missing feature in my opinion is being able to install a vimrc to your vim editor online get back all the keybindings you're used to. Another really important missing feature of a vim editor online is being able to save files easily and navigate between files easily.
What would really be cool is being able to edit files from the filesystem, using the WASI API. Even if direct access to the filesystem isn't possible, an autosync with the source code so that you could easily test the code would be super cool.