This was done in EtherPad and there were a couple HN threads at the time:
The most surprising thing I've seen in 2009, courtesy of Etherpad - https://news.ycombinator.com/item?id=495336 - Feb 2009 (126 comments)
Watch Paul Graham write his latest essay - https://news.ycombinator.com/item?id=557191 - April 2009 (22 comments)