By Paul Festa, CNET News.com

Yahoo quietly released a new version of its instant messenger software, jazzing up the chat interface for users while expanding marketing opportunities for advertisers.

Yahoo made Messenger 5.0 available for download this weekend, in the process launching its new IMVironments, or themed animated backgrounds for chat windows.

A test, or beta, version of the messenger launched in October.

The new interface options let two people with YIM 5.0 installed trade messages in richly illustrated and sometimes animated and interactive windows. The themes range from a generic animated snowfall to branded themes by the rock band Garbage, the Nintendo video game Super Smash Bros. Melee, and the new Disney and Pixar movie, Monsters Inc.

More of the article can be found at Yahoo News