America Online Inc. on Thursday launched in beta an overhaul of its instant messaging client that expands the product's communication capabilities to include enhanced PC-to-PC voice and streaming video messaging and media file transfers.

Code named "Triton," the software is expected to be generally available before the end of the year, the Dulles, Va.-based, Internet service provider said. In the meantime, users of AOL Instant Messenger can expect to see one more upgrade of the current 5.9 version.

With Triton, AOL, a subsidiary of Time Warner Inc., has reengineered the AIM client with a new code base and architecture, in order to enhance advanced communication services, such as real-time voice and video.

"It's a brand new world out there, and we needed a much more advanced communications environment," a spokeswoman said.

Triton, over time, will become the AIM client, replacing all other versions. With 20 million active AIM users, the service has become the primary driver behind web traffic to other AOL online products, such as news, music, job listings and CityGuide, which lists local businesses, points of interests and other locations, and also provides maps and directions.

The beta client has a tabbed messaging interface for easy transition from text to mobile instant messaging or PC-to-PC voice communications over a broadband connection. Users will eventually be able to launch real-time video sessions, share files or images and invite other users to play games with one click, AOL said.

The software also supports multi-party voice communications and new "IM Catcher," which corrals messages into a single interface to help users screen and manage their IM sessions with multiple people.

Triton is available through AOL's public beta test site.