With AIM 4.5, users can send and receive text messages and participate in private or group chat rooms, AOL said in a statement. In addition, with AIM's Buddy List feature, a user can see when friends and co-workers are online, providing the user has added them to his or her private list. Other features include the ability to allow only certain people to see when a user is online, automatic alerts when new e-mail arrives in a user's mailbox providing AOL Mail is used, and customised news and stock quotes.
When asked when the final version of AIM 4.5 for Mac OS X will be released, AOL spokeswoman Jane Lennon said: "We haven't got a date yet. We will continue testing it. Each product is different."
There are 84 million registered AIM users in the world, according to AOL estimates. These are users for all platforms; AOL doesn't have numbers of users broken down for different platforms, Lennon said.
Lennon could not say how many new AIM users AOL is expecting following Friday's beta release.
Internet service provider AOL is a wholly owned subsidiary of media giant AOL Time Warner, Inc., and based in Dulles, Virginia.
Apple's long-awaited Mac OS X was released on March 24. The new version of the free AIM 4.5 service can be downloaded by Mac users at www.aol.com/aim, AOL said in a statement.