What is the difference between Comet Technology and SignalR

Question

I was looking for this very badly ... Can someone please tell me what is the exact difference between SignalR and Comet Technology ... I know that Comet is doing the same Client-Server Communication as SignalR ... It is pushing data the client is the same as SignalR, then what is the difference between 2. Please help.

Thanks!!! Sivanand Aurur.