Yahoo! Messenger (sometimes abbreviated YIM or YM) is an advertisement-supported instant messaging client and associated protocol provided by Yahoo!. Yahoo! Messenger is provided free of charge and can be downloaded and used with a generic "Yahoo! ID" which also allows access to other Yahoo! services, such as Yahoo! Mail, where users can be automatically notified when they receive new email. Yahoo! also offers PC-PC, PC-Phone and Phone-to-PC service, file transfers, webcam hosting, text messaging service, and chat rooms in various categories.
Yahoo! Messenger was originally launched under the name Yahoo! Pager on March 9, 1998.
In addition to instant messaging features similar to those offered by ICQ, it also offers (on Microsoft Windows) features such as: IMVironments (customizing the look of Instant Message windows, some of which include authorized themes of famous cartoons such as Garfield or Dilbert), address-book integration and Custom Status Messages. It was also the first major IM client to feature BUZZing and music-status. Another recently added feature is customized avatars. Yahoo! Messenger also allows users to access Yahoo! Chat Rooms.
Voicemail and file sharing
Yahoo! added voicemail and file sending capabilities to anywone. File-sharing of sizes up to 2GB was added to Yahoo Messenger.
As of 8.0, Yahoo! Messenger has added the ability for users to create plug-ins (via the use of the freely available Yahoo! Messenger Plug-in SDK), which are then hosted and showcased on the Yahoo! Plug-in gallery. Yahoo now no longer provides plugin development SDK.
Yahoo! Music Radio
Yahoo! Messenger users can listen to free and paid Internet radio services, using the official Yahoo! Music Radio plug-in from within the messenger window. The plug-in also player functionality, such as play, pause, skip and rate this song.
Yahoo's software now allows users with the most current updated versions (messenger 8 through 10) to utilize its webcam service. This option enables users from distances all over the world to view others who have installed a webcam on their end. The service is free with provided speeds averaging from a range in between 1 to 2 frames per second. The resolution of the images can be seen starting at 320 x 240 pixels or 160 x 120.