Yes, it is. That's an extremely old version I wrote as a "let's see if I can do this" project. You can see the newer one by browsing the subversion repository, which unfortunately is broken until I commit the fix tonight.

I'm working on integrating it with Google docs so that you can work on your documents using a vi/emacs-like editor, which is extensible just like emacs except using javascript rather than elisp.

I hadn't seen yi, but it looks very similar to what I want to do, which is combine the best of vi and emacs into a new editor. I'm particularly interested in decent web-based editors, however; the implementation language is secondary.