Instant messaging clients

MSN Messenger
MSN®Messenger
        for Windows®
 
Send instant messages with cool, emoticons, call anywhere in the world from your computer, see when someone's typing, page a contact's mobile phone, send pictures and music to your friends, and much more. MSN Messenger

Yahoo MessengerYahoo Messenger

 

 

AOL Instant Messenger

Article on Instant Messaging.