Facebook carrying instant messaging is big news. And it’s not the news people at Microsoft, AOL or Yahoo want to hear, since it’s likely to affect their dominance in the IM market. However, as Facebook gave somedetails about the forthcoming service, it became obvious that it will have limitations. The chat can only be between individual members, the Financial Times stated,there will be no chat rooms, and users won’t be able to chat with those who don’t have a Facebook account. But it will be free. A few developers had put together chat programs forFacebook, taking advantage of the opportunity when the company opened up the site to applications, and they’re likely to be the big losers in this. Matt Cohler, Facebook’svice-president of product management, pointed out that users could still use the developers’ services if they desired. “We develop our applications at parity with other developers.Users can remove any of our applications if they want and swap in another feature instead.” With some 60 million users, Facebook chat could become a major online thing.