"That's the sort of tacit social experience that's not available on a Web browser today," said Donald Fisher, senior product manager at Red Hat.

Another feature, Music Radar, monitors what songs you are listening to on iTunes or Yahoo Music Engine, also searching those playlists, in order to share them with other Mugshot users. Red Hat is developing a similar feature for video clips. Fisher downplayed any competition with Web consumer players such as Yahoo Inc. or Google Inc.

"We're keeping this purely additive, so that our software interoperates with everyone else," he said.

On the One Laptop per Child initiative, Red Hat has been able to shrink down its operating system, which normally requires 1.3GB to install, to about 250MB, according to engineering manager Chris Blizzard.

It aims to bring a working operating system with essential applications such as e-mail, the Gecko Web browser, document-creation software and a VoIP application, down to 130MB by the end of the year. That will allow users of the laptop, which is expected to have 128MB of RAM and 500MB of flash memory storage, to have more than 350MB of storage available for documents, photos and more.