Google is “dropping the mother of bombs on its chief rival, Microsoft,” said MG Siegler in TechCrunch. The Internet giant is launching an open-source operating system, Google Chrome OS, that will go head-to-head with Windows, especially on increasingly popular, low-cost netbooks. “It’s a genius play”—people want a lightweight and fast OS, and most netbooks are running 8-year-old Windows XP. Microsoft better hope Windows 7 is a big hit.

It’s predictable, and understandable, that people are seeing this as a “new, major assault” on Microsoft, said Rob Hof in BusinessWeek. But I don’t think that’s Google’s “main aim.” As with its Chrome browser and Android mobile OS, Google is “trying to simply make the Web work better.” That’s not “altruism”—when people use the Web, Google profits.

This is about the Web, but that shouldn’t make Microsoft rest any easier, said Stephen Shankland in CNET News. Chrome OS, which essentially runs the Web over a Linux base, is cloud computing taken to the next level, and it shows that Google believes Web applications—think Google Docs, Gmail, and Google Calendars—are the future of computing. If Google’s right, Chrome OS could spell trouble for Microsoft Office, too.

Microsoft isn’t taking this lying down, said Tom Warren in Neowin. Recently, the software giant has been “dropping hints” about its experimental Gazelle browser, which is being designed to act “like a self-contained operating system.” If Chrome OS gets a lot of positive press, look to hear more about Gazelle.