If I wanted to build a chat application that can chat with other users that are on the website and host chatrooms what would be some ideal ways? If there are some open source ones out there? If I build from scratch what should I use (i heard comet is good)? Thanks!
If you are planning to build one by yourself, looks at the Subscribe and Publisher pattern. You can use remoting or just socket programming with a centralised server to capture and transmit messages to the respective users.