JS-based S2 editor with syntax highlighting?

[pauamma]

Can someone who groks JS better than I do check whether http://code.livejournal.org/trac/livejournal/changeset/20330/trunk and http://code.livejournal.org/trac/livejournal/changeset/20331/trunk is a browser-based syntax-highlighting S2 editor? (Or part of one, maybe?) I kinda want to submit a suggestion for something similar, if it is, but I can't do that without having some idea of what it does.