Program for instant text messaging, for audio and video between the interlocutors, as well as transfer files to each other. From features - the ability to customize the appearance using "themes", as well as support for webcams, which allows not only hear but also see companion. In addition, Yahoo! Messenger vtoroena system calls from PC to phone - not free, but the cost of such a call is lower than "normal".
Another feature of the program - extension plug-ins (currently they released about two hundred). Recently Added support for interoperability with Windows Live Messenger.

Connect with all your friends: Instant message with friends on Yahoo!, Windows Live Messenger and more. Show off your status: Easily add links and emoticons to your status messages. Watch videos together: Share videos from popular sites and watch them with friends right in your IM window. More Features: Instant message with one friend, or conference in a bunch. Send text messages (SMS) to friends' mobile phones for free. Join a chat room to meet new friends while you discuss your favorite topics. Make free PC-to-PC calls and PC-to-phone calls for as low as 1? a minute (plus free voicemail!). Use the built-in media player to watch web videos and view photos with friends. Show your style with emoticons, Avatars, audibles and IMVironments.