I am using VSTS 2008 + ASP.Net + Forms Authentication + .Net 3.5 + IIS 7.0 + C# to develop a Web Application. I want to add web based instant messenging feature to my web application (using Forms authentication), I just need very basic features, like text based message, user presence status, etc.
I want to know whether any ready-to-use and easy to integrate components? Better open source.
Jabber/XMPP is open-source, there are many implementations (client and server) that are mostly open source. Just check out XMPP Standards Foundation.
By the way, You'll find a list with implementations of web-based clients here.
Also, there's a mono/.NET-implementation, called jabber-net.
来源：https://stackoverflow.com/questions/1538913/open-source-instant-messenger