As far as we're aware, this is the ONLY existing implementation of character-at-at-time chat available anywhere on the web; we looked pretty hard and couldn't find any, so we wrote this to scratch our own itch. (The best we'd come up with prior to this was a shared etherpad doc.)
We would love help (a) making sure this scales to high loads and even more crucially (b) getting it to work under IE8.