Redesigned webcam, new friend-happy design, PC-to-PC voice calling, Yahoo! Mail...
New in v9.x:
Completely redesigned webcam (new features include ability to swap video windows, position the video windows side-by-side, mute the call or place it on hold, full screen option for video calls), Y! Updates view in contacts list (view Twitter updates and other information), all new Yahoo! Insider, new ways to sort contacts (v10.0); new friend-happy design, with more room for friends' images, information, and updates; support for new Emoticons and plus new skins, ability to use Flickr for swapping photos; Release Notes - Last Updated: 09.30.09 (v9.0.0.2162 / v10.0.0.542 Beta)
Upgrade Meter:3
New in v8.x: Contact Search Bar, ability to make PC-to-phone calls (at low rates), ability to give your PC a phone number for people to call (for monthly charge), support for listening to free Yahoo! Music LAUNCHcast radio; Release Notes - Last Updated: 09.07.07 (v8.1.0.421)
Upgrade Meter:5
New in v7.0: Free worldwide calling over the Internet, drag-and-drop photos feature, enhanced capabilities for adding and inviting friends to Yahoo! Messenger; Release Notes - Last Updated: 08.09.05 (v7.0.0.426)
Upgrade Meter:5
New in v4.0: Support for making inexpensive international phone calls, recent history and message archive, Nicknames support, send contact information feature; Release Notes Upgrade Meter:5
New in v3.5: Yahoo Companion for sending IMs from your browser, Yahoo Messenger Tour for new users, various bug fixes and minor feature enhancements
Upgrade Meter:4
New in v3.0: Make free pc-to-phone calls in the U.S., new chat client, IM window with toolbar buttons, emoticons (smileys for use in IMs), font effects; Release Notes Upgrade Meter:5
New in v3.0 Beta: Improved voice chat (now full duplex with handsfree support), status icons (for displaying whether your online friends are busy or idle), integrated member directory search, tabs for calendars and auctions; Release Notes Upgrade Meter:3
New in Beta Build 754: Minimized message option (minimizes to system traybar icon), e-mail and online/offline notifications for friends (from system traybar icon), improved themes support, configurable fonts and colors for messages; Release Notes Upgrade Meter:3
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