Overall, Yahoo! Messenger has a great deal to offer anyone looking for a chat client with instant message capabilities and more. Both AOL Instant Messenger and Yahoo! Messenger offer many of the same features, but each differs in its approach. We recommend downloading both clients to get a better idea of which one better matches your individual preferences.
Pros: Freeware, strong feature-set, voice chat capabilities, integration with Yahoo
Cons: Must first register with a Yahoo! server, lacks built-in support for chat rooms