Chrome usage within striking distance of Firefox

If one in 50 people on the Web move from Firefox to Chrome, Google's browser will unseat Mozilla's for the No. 2 spot in worldwide usage.

That's because, according to Net Applications' November browser usage measurements, Chrome is now within 4 percentage points of Firefox. With a 2 percentage-point increase in one and a 2 percentage-point decrease in the other, Google comes out on top.

Firefox dropped 0.4 percentage point to 22.1 percent of usage in November, while Chrome gained 0.7 percent to 18.2 percent. If that rate was to continue, Chrome would outpace Firefox in March 2012, but fluctuations make such predictions difficult.

Firefox once was the prime challenger to Microsoft's Internet Explorer, which for years languished in the doldrums of software development. Now it shares that role with Chrome and, to a lesser degree, Apple's Safari. Microsoft is in high gear again, though, with IE9 a credible challenger and IE10 shaping up to be a strong competitor when it's finished in 2012.

The browser market is now fiercely competitive as browser makers use the software to drive their agendas. For Microsoft, it's about the Metro user interface in Windows 8; for Google, it's browsing speed and Web applications; for Mozilla, it's a Web built on openness and standards; and for Apple, the best mobile devices.

In November, IE's steady decline stopped, with Microsoft's browser holding steady at 56.2 percent of usage. Microsoft has largely written off Windows XP users by requiring Windows Vista or Windows 7 for its current IE9. The company measures its performance by Windows 7 usage. there, IE9 passed Chrome and Firefox in usage and now trails only IE8.

The vast majority of browser usage today is from personal computers--92.2 percent. But with smartphones and tablets, mobile-device usage is generally increasing. In November, it reached a record 6.7 percent, according to Net Applications.

The top mobile browser by far is Apple's Safari, but it plunged 7 percentage points to 55.0 percent of usage in November. The Android browser had bumped Opera Mini aside in October for the second-place spot, but in November, Opera Mini clawed its way back. Opera's lightweight browser, which runs on thousands of phones, surged 7 percentage points to 20.1 percent, while the Android browser dropped 2.2 percentage points to 16.4 percent.

Opera also offers a full-fledged browser, Opera Mobile, for higher-end smartphones. But that remains relatively rare at 0.4 percent of mobile browser usage.