Starting in the second quarter of 2006, the millions of users of Microsoft’s MSN Messenger and Yahoo! Messenger will be able to interact with one another as if they were on the same network, the companies said.

IM has been one of the most popular and enduring aspects of Internet use since the dotcom boom of the 90s. And Wednesday’s news could be the first step toward the end of one of IM users’ biggest complaints: walls blocking interaction with members of competing networks.

Matt Anderson, an analyst with The Raticati Group, a technology market research firm, said rumors had pointed toward Microsoft announcing an IM "interoperability" deal with market leader AOL, not Yahoo!

"It was somewhat surprising but I think it’s definitely where people would like to see the market headed," Anderson said. "It definitely puts some pressure on AOL to open up their customers."

AOL’s IM service, AIM, remains the dominant IM service in the US. Worldwide, Yahoo! and Microsoft’s networks are bigger, according to comScore Media Metrix, a research firm.

AOL’s global market share through AIM and its other sister IM network, ICQ, is 56 percent, Anderson said. MSN and Yahoo’s share is 25 percent and 19 percent, respectively, he said.

Since 2001, AOL has discussed efforts to open up their network to other IM providers but has yet to do so.

Google launched its own IM service, Google Talk, last month.

When it comes to gaining ground in the U.S. market, the IM habits of students in Linda Antinone’s pre-calculus class at Paschal High School show Microsoft and Yahoo! have their work cut out for them.

When asked which IM software they used, most of the class replied in unison, "AIM."

"That’s what everyone else uses," explained Ernest Elbert, 15.

One student said he had once checked out Microsoft’s IM program and liked its sleek design, but still couldn’t foresee switching platforms since all his friends were using AOL’s service.

In a couple of years, many of Antinone’s students are likely to become members of Facebook.com, the wildly popular online directory for college students. Last week, AOL announced a deal to be the exclusive IM provider for Facebook.com.

"That will just further strengthen their presence there in the United States," Anderson said.

Source: Batheja, A. "Microsoft, Yahoo to connect instant messaging networks." Star-Telegram.com. Posted on Wed, Oct. 12, 2005. 9-13-2005. http://www.dfw.com/mld/dfw/12885563.htm