Thanks. I started to look into Pyjamas which is all goodness of GWT but written in Python. Node.js and Restify look good. I will need to explore more on these. The main reason I wanted to have multithreading in my app was to send notification emails on a separate thread than the main one, when an action is taken by a particular user and others interested in that action and are subscribed for notifications. It's like follow/notify model. I haven't found a solution for this yet.