SignalR is the latest in a long string of new technologies pouring out from the ASP.NET team recently, when Microsoft rolled out version 1.0 of SignalR when Visual Studio Update 2 was announced. In a nutshell, SignalR is technology for .NET that allows you to build real time, connected Web applications. Connected in the sense that you can build Web applications that can send and receive and broadcast data in real time. The canonical example of a 'connected' application is a chat application where a client can broadcast messages to all other connected clients. While that's pretty cool in and of itself, that only begins to scratch the surface of what's possible with SignalR as you can communicate in a wide variety of ways between client and server and between all clients to push data around.