Yahoo Mail Beta - What did they use to develop this application and is it possible to replicate w/RoR?

Hey guys,

I was wondering what was used (programming language(s)) to develop a rich app like Yahoo Mail Beta ([http://advision.webevents.yahoo.com/mailbeta/

](http://advision.webevents.yahoo.com/mailbeta/)) and if it’s possible to do something like this with RoR with conjuction with Ajax. Any thoughts?

thanks,