FlexWebSocketDemo is a project mainly written in ACTIONSCRIPT and PERL, it's free.
flex AIR app - socket.io client
Get nodejs builds for windows, use it on linux on saparate computer or use virtual machine. Get socket.IO-node - start demo chat server.
Install Flash develop. Open the FlashWebSocketDemo.as3proj project. You need to set your local IP address or domain name. Compile it. Now u can connect to chat server with AIR app, and make multiuser chat adding more users in different browsers.
For more information - http://nasko7.blogspot.com/2010/10/how-to-connect-air-app-to-socketio-chat.html