The emerge toolkit is a state-preserved web development framework. Build your whole application in one easy place. Uses O/R Mapping on the back-end, and Comet-style sockets on the front. http://emergetk.com
Ever wanted to create notes for pages on the web and be able to share them? This framework allows to create annotations to XML and HTML documents. Annotations are independent of presentation and can be traced back even if part of the document changed.