While Google is adamant that Chrome OS is a separate project with a separate design goal and not meant to replace Android, observers have wondered why Google would choose to form two OS projects for netbooks rather than adapt Android for netbooks and PCs, especially while some developers already have ported the OS to netbooks.

In its blog post explaining what Chrome OS is on Wednesday, Google continued to attest that Android is suitable for netbooks, while explaining the difference between it and Chrome OS.

"Android was designed from the beginning to work across a variety of devices from phones to set-top boxes to netbooks," the company wrote. "Google Chrome OS is being created for people who spend most of their time on the Web, and is being designed to power computers ranging from small netbooks to full-size desktop systems."

The decision to create a different OS for netbooks rather than continue the work being done around Android "caught me off guard," said Frank Gillett, an analyst with Forrester Research. "I thought that, given that Android was based on Linux, they'd be able to stretch it," he said.

Indeed, others wondered why Google felt the need to create two OSes targeted at the netbook market, especially since Android is still relatively new and does not yet have a strong position in the mobile market against Apple's iPhone and other smartphones.

"If I was going to take a stab at it, I would say that it's a matter of Google wanting to emphasize Chrome, and/or perhaps not wanting to confuse people about Android's suitability for environments besides handsets," said David Kirkpatrick, a New York-based independent software architect who has worked with Linux for more than 10 years.

Indeed, the Chrome browser is at the heart of the Chrome OS, and Android does not even use that browser in its environment, though it does include one based on the same WebKit open-source platform that the Chrome browser is based on.

Google's argument for two OS projects is that the Chrome OS marks an entirely new way of thinking about the operating environment for netbooks and PCs -- with the browser at the center of the OS. All applications built for Chrome OS will be Web-based and thus able to be accessed from any browser, according to Google.