Mozilla's Firefox and Apple's Safari web browsers both continued to snare market share from Microsoft's Internet Explorer last month, a web metrics company said.

According to Net Applications' February data, both Firefox and Safari ate slightly larger slices of the browser pie than in January. IE, on the other hand, slipped by nearly the same amount.

Firefox, which has versions for Windows, Mac OS X and Linux, climbed to 14.2 percent from January's 13.7 percent. Safari, which is bundled with Mac OS X, rose to 4.9 percent from 4.7 percent. IE's share dropped to 79.1 percent from 79.8 percent.

"After a minor hiccup in January, Firefox seems to be back on the offensive in February," Vincent Vizzaccaro, Net Applications' executive vice president of marketing and strategic relationships, said in an emailed newsletter. "January showed a brief halt to Firefox's assault on Microsoft Internet Explorer's market share. Could that have come from new Vista machines? Possibly, but it appears that browser users have gone back to switching to Firefox, Safari and Opera."

Opera, a browser from a Norwegian company by the same name, increased its market share slightly, from 0.73 percent to 0.79 percent.

The newest versions of both Firefox and IE also boosted their share during February. Firefox 2.0, released last November, climbed to 7.8 percent, a 1.5 percent one-month gain. IE7, which runs on both Windows XP and Vista, increased to 29.1 percent.

But the take-up of IE7 has slowed substantially over the past four months. Released to XP users in late October 2006, IE7 has been pushed by Microsoft as a high-priority update through Windows' built-in Automatic Updates, one reason why IE7 use leaped nearly 10 percent from November to December and by more than 7 percent from December to January. IE7 adoption has slowed since then; it rose by only 4 percent from January to February.

Charts that show Net Applications' most recent data are available online.