Integrating Instant Messaging into an ASP.NET application

I was thinking about integrating some instant messaging function into an existing ASP.NET web application, e.g:

• the web application can display the online-status of users (are they currently logged in with their IM client)
• users can send messages from the web application to the IM client of other users
• users can initiate a IM chat from the web application (without having to know the other user's IM identification beforehand)

Does anyone know about some existing libraries, sample applications or other resources that might help implementing such a feature?

Thanks a lot for sharing your knowledge.

You should try Jabber. Demo client avaiable here.

There is an architectural overview, the main concept looks like this:

_{(source: webta.net)}

And some citation from the site:

• 1. Goal Create an multi-service instant messaging AJAX-based web application with internal accounting.
• 2. Main problem We need to connect to IM servers from HTTP client (browser). HTTP is a stateless protocol. This means that, theoretically, each HTTP request is being proccessed by separate http daemon proccess. Once request proccessed (data sent to client), server fogets about client. All IM services protocols are stateful. When client connects to IM server, socket connection being created and connection much remain open for succesfull communication.