The most surprising thing about Google's new Chrome browser is that it's taken so long for it to appear. After all, the browser has been central to practically everything that Google does, so it would be foolish to allow others to control it.
Google's relationship with Firefox may be good, and their intentions reasonably closely aligned, but it's no substitute for controlling your own destiny.
Since the reason for holding off from releasing a home-grown browser certainly wasn't technical, I suspect the main motive was political. If Google had come out with a browser five years ago, Microsoft would have squawked – with some justice – about unfair advantages and bundling. Today, with Firefox holding around 20% of the browser market, Google can claim with a certain plausibility that its Chrome will be a minor player in comparison.
Aside from taking back control, it's fairly clear what Google is trying to achieve with Chrome. In fact, the Google blog announcement was quite frank:
On the surface, we designed a browser window that is streamlined and simple. To most people, it isn't the browser that matters. It's only a tool to run the important stuff -- the pages, sites and applications that make up the web. Like the classic Google homepage, Google Chrome is clean and fast. It gets out of your way and gets you where you want to go.
In a sense, Chrome is not a browser, it's an anti-browser. It's mission is to destroy the concept of the browser, and become a frame for other applications – or, more pointedly, a kind of "chrome" window. In other words, Chrome is the long-awaited Google OS, a way of running Web-based applications like Gmail, Google Docs and the rest (the inclusion of Google Gears, which allows such apps to be used offline, is a big clue here). That Chrome's default function is as a browser is almost a historical accident.
That's why I don't think Chrome is a threat to Firefox, at least not in the short term. Even if Chrome takes off and becomes as reflexive as Googling, I expect many people will stick with Firefox as their browser. There are lots of reasons why they should – for example, the fact that Firefox aims to optimise the browsing experience, not to function as a pseudo-operating system layer.
In addition, the huge number of really great browser extensions now available means that giving up Firefox will be painful for many who have come to depend on one or other of them: even assuming Chrome develops as rich an ecosystem, it will be some time before it matches Firefox in this respect (the old momentum problem, which has also been a significant brake on Firefox uptake by Internet Explorer users who want to keep familiar ActiveX controls.)
Just as important is the developer side of the equation. Firefox extensions are written by a band of dedicated coders who have grown to know and to like Firefox: I don't think many of them will jump ship to Chrome just because it's Google. On the contrary, Firefox is widely supported precisely because it doesn't come from a big company; Chrome is bound to be viewed with a certain suspicion in the free software world, giving Firefox an edge in terms of developer loyalty.
Google also seems to have been careful to flag up its non-hostile intent by agreeing to a three-year extension of the deal with Mozilla that provides the latter with most of its income. If it really wanted to weaken Firefox, it could have chosen to keep it going for only one year, or not to have renewed it.
The real loser, of course, is Microsoft. Even though it has responded in part to Firefox by starting to make Internet Explorer more attractive in its own right – rather than simply the default that everyone got and therefore used – it's still by no means achieved parity. Google's Chrome will not only make the browser market even more competitive – something that will frankly be good for Firefox, too – and hence challenging for Microsoft, but will also attack more directly Windows' grip on the desktop.
Against that background, Chrome looks a potentially an exciting project. By doing something very different from Firefox, it challenges the latter to think through what exactly its mission is.
Since Chrome is open source, and builds on other free software projects (including Firefox), it is not undermining the larger open source ecosystem, even if it does eventually prove problematic for Mozilla. My only regret is that for this otherwise innovative project Google adopted a truly conventional release plan: Windows only to begin with, and Mac and GNU/Linux later.
Update: Wired has published a detailed story about the background to Chrome's creation. Key quotation:
From the beginning, the Chrome team hoped that its visual presentation would be so understated that people wouldn't even think they were using a browser. The mantra became "Content, not chrome," which is sort of weird given the name of the browser.