Tornado is an open source version of the scalable, non-blocking web server and tools that power FriendFeed. The FriendFeed application is written using a web framework that looks a bit like web.py or Google's webapp, but with additional tools and optimizations to take advantage of the underlying non-blocking infrastructure.
"Lucid is a free, open source web desktop, or webOS that lets you:
Access your media, office documents, and other files anywhere
Stay up to date with Twitter, RSS feeds, and what's happening on the web
Create great web applications in ridiculously short amounts of time"