Am I missing something, what does that HN article have to do with $100k? EDIT - never mind, I missed the connection! Good call.

I like the concept of this app, but it seems from their blog that they were having a hard time charging for this service. Without that model in place, like earle mentioned, this isn't really a startup - but for the right person it could be I think.

Thanks for your question. We tried ejabber but it was just less friendly than Openfire. We used XMPP4R with Starling for the queue to have a fast interaction between the web and IM. Plus, we used the ORM Rails to access the DB from the listener (the bot), written in pure Ruby.