I used tornado load balanced by haproxy for the Web servers instead of Django. Backend is mongodb and I use a small tornado driven zeromq to manage passing updates between the front ends real time. That router also does all the db writes.
I built it in my spare time (and it shows) just to have a place to take twitter conversation to get around the 140 character limit
Not sure why you would need to seek funding to open source something like this. Today's frameworks make it pretty easy. Is there really enough need for another chat server? One motivation for me was to play with zeromq and tornado together. There are already other more robust and stable chat solutions out there. I never even considered there would be enough interest in it to open source my app.