Here are a couple of links that would get one up to speed to test or develop using the open sourced Tornado Python non-blocking web server and framework:
In what regards the web framework, Tornado seems to sit somewhere between web.py or Google App Engine simplicity and Django feature richness. There isn’t any mention about data storage access, so I assume that you can pick whatever solution you’d like. I must confess that I would still like to see their data access layer considering the storage model FriendFeed is using.
Now, Tornado’s strongest point seems to be its non WSGI compatible, non-blocking web server implementation, which seems to perform quite well (at least for those trivial tests).
