Google is taking on Microsoft's core business -- Windows. Late Tuesday, Google said it was working on a competing operating system called Chrome OS. Here is that story. Here is the Google announcement, which gives a manifesto for itsoperating system.

"... We hear a lot from our users and their message is clear — computers need to get better. People want to get to their email instantly, without wasting time waiting for their computers to boot and browsers to start up. They want their computers to always run as fast as when they first bought them. They want their data to be accessible to them wherever they are and not have to worry about losing their computer or forgetting to back up files. Even more importantly, they don't want to spend hours configuring their computers to work with every new piece of hardware, or have to worry about constant software updates. ..."

Microsoft has no comment right now. Company representatives said they expect to have something to say shortly.

Update 2:35 p.m.: Microsoft says itwon't be commenting about Google throwing down the gauntlet.

Matt Rosoff from Directions on Microsoft, an independent analyst firm in Kirkland, said, "If anybody has a chance to be successful with an open-source operating system, it's Google." The key question, he said, is "whether Google is serious or whether this is just another hobby." like the Chrome browser.

Rosoff says if Google were to provide technical support and marketing that computer makers would want, that would be a sign that it'sserious about an operating system.