Microsoft's Internet Explorer (IE) lost nearly a full percentage point in market share during August, the browser's biggest drop in three months, NetApplications has confirmed.
Rival browsers, including Firefox, Safari and Opera, all saw their marketshare's grow in the month.
But all those browsers, Microsoft's included, now face competition from Google's Chrome browser, which immediately grabbed one percent of the market, Net Applications said.
Internet Explorer accounted for 72.2 per cent of the browsers used in August to access the 40,000-plus sites Net Applications monitors. That was a drop of about 0.9 percentage points from July, and a departure from the month before, when IE maintained its share for just the third time in the past year.
IE's August drop was the second-largest for the year, lower only than May's 1.1-percentage point fall.
"I can't really explain what happened," admitted Vince Vizzaccaro, Net Applications' executive vice president of marketing. "Perhaps there was some relationship with the launch of IE8 Beta 2. If users are looking at IE8, maybe they're looking at other browsers at the same time, trying to decide which one to use."
Meanwhile, Firefox increased its share by about half a percentage point, climbing from 19.2 per cent in July to end August at 19.7 per cent . Other browsers also boosted their shares: Apple's Safari went from 6.1 per cent to 6.4 per cent , while Opera's share hit 0.74 per cent , up slightly from July's 0.69 per cent .
Within IE's and Firefox's totals, however, there were shifts from one version to another.
As Vizzaccaro hinted, Microsoft's share for its IE8 browser --still in beta - climbed by almost 500 per cent in just a few days. The number of users running Firefox 3.0, the latest version of Mozilla's open-source browser, also jumped last month, moving from 5.7 per cent in July to 7.7 per cent by the end of August.
Mozilla started offering Firefox 2.0 users an update to Firefox 3.0 last week. Not surprisingly, Firefox's month-to-month gain came in increases to Firefox 3.0's portion of the browser's share.
IE7, officially released in October 2006, slid slightly in August, falling from July's 47.1 per cent to 46.8 per cent. It was only the second time that IE7 lost market share in the last 24 months, according to Net Applications.
The even-older IE6 continued to lose share in August, ending the month at 25.2 per cent, off from July's 25.7 per cent.
Google Chrome, accounted for 1.04% of all browsers as of 1pm Eastern today, said Vizzaccaro.
"But their numbers will be a lot easier to grow quickly," he said, "than, say, Safari or even Firefox did."
Vizzaccaro cited Google's name recognition and dominance in the search field as two reasons why it would be able to show rapid uptake for Chrome.