|AIM (AOL Instant Messenger)||
AIM (AOL Instant Messenger)- is a well-known IM tool.
http://beta.aol.com for the latest beta.
Native alternatives for non-windows platforms
- Kopete (KDE's IM client. Supports AIM, Yahoo, MSN and many others!)
- Adium (OSX application. Supports a plurality of protocols)#
Note: AIM has a Linux version, but its features lag way behind the Windows version.