Maybe not so useful for those who mainly chat from their own PC at home, or a laptop with it ready installed, but good if you travel a lot and use computers where the client software isn’t and can’t be easily installed.
It’s built using Flash, so it should work on most modern browsers where the computer has that installed.
Messenger for the Web has some features not available on the PC version, such as tabbed chat windows and saving conversations on Yahoo’s own servers, though it lacks video, file transfer, and voice communications.
It’s still compatible with Microsoft’s Live Messenger system.
Launched today in the US, Brazil, India, Malaysia, the Philippines, and Vietnam, it will roll out to other countries in due course.