Another month rolls round, bringing with it another bunch of browser market share statistics. July was the first full month during which Firefox 5 was available, so it was the first indication of how well Mozilla's new Rapid Release schedule would play in the market.

First the overall market share numbers. Internet Explorer is down 0.87 points to 52.81 percent. Firefox is down 0.19 points, to 21.48 percent. Chrome and Safari both made gains, of 0.34 and 0.57 points each, to 13.45 and 8.05 percent respectively. Finally, Opera fell slightly, by 0.08 points to 1.65 percent.

At this rate, Internet Explorer is going to lose its majority position by the end of the year. It will still be the most-used browser, by quite a margin, but its days of dominating the Web are by now a distant memory. Firefox's market share fell slightly, but so far, at least, there's no sign of any substantial abandonment of the browser. Enterprise markets may indeed dislike Mozilla's update policy—though we argue that they shouldn't—but that doesn't appear to have made much difference to the number of users the browser enjoys.

Microsoft and Mozilla's losses appear to be Google and Apple's gains. Both WebKit browsers picked up new users during July. Google continues to widely advertise Chrome, and its browser has won significant mind-share among technical types—a factor no doubt proving influential. Safari was updated in July, a consequence of the release of Mac OS X Lion, and it has likely picked up some share from people giving the new version another chance. Opera's losses this month were not as severe as those experienced last month, but the browser has nonetheless suffered a significant drop over the last three months.

The version breakdown follows the familiar trends of the last few months. Internet Explorer 6, 7, and 8 dropped, by 0.94, 0.29, and 0.77 points respectively, while Internet Explorer 9 gained 1.14 points. Firefox users appear to be transitioning smoothly from version 4 to version 5; the older version lost 8.06 points, its successor gained 8.34. The older versions of that browser both fell, with 3.5 falling by 0.44 points, and 3.6 by 0.13 points. Usage of 3.6 remains significant, however, with 6.95 percent of Web users sticking with it.

July's numbers suggest that Firefox users have become fragmented into two groups: the old, using 3.x versions, and the new, using 4 and 5. The latter group appear to be playing the upgrade game and transitioning from one version to another at a healthy pace. But the 7-odd percent of users sticking with old versions are showing no signs of upgrading. 3.6 remains supported and patched, so many users—particularly in the enterprise—might not see any compelling reason to upgrade just yet. The real test for the rapid release schedule will be Firefox 6, due in the middle of this month. There was a three-month gap between versions 4 and 5; the interval between 5 and 6 will be around six weeks, making the risks of upgrade fatigue that much greater.

Microsoft is continuing to struggle to win people over to its new browser. Internet Explorer 8 users are upgrading and are apparently happy with the release, but Chrome and Firefox users appear to continue to prefer their current browsers. There is one promising trend for Redmond, however, and that's Windows 7. On its latest and greatest operating system, it looks as if Microsoft has stopped the rot. Over the last four months, Internet Explorer's share of Windows 7 users has slowly crept up, from 67.25 percent in April, to 68.05 percent in July. These gains are small, and with Windows 7 only installed on around 28 percent of Internet users' computers, they're not enough to offset the losses made on other platforms. The gains do show that when given the chance—an operating system that supports Internet Explorer 9, and no legacy applications demanding the user of an older browser—Web users are happy to use Microsoft's newest browser.

The mix of operating systems used on the Web reached a landmark during July. Windows XP, the operating system that was first released a decade ago this month, dipped below a 50 percent share. After years at the top, Microsoft's ancient operating system is now used by 49.84 percent of Web users. It's still the most widely used operating system, but Windows 7 is gaining fast, and at current rates, by next August Windows 7 will have passed its ancient predecessor.

Chrome's transitions are as smooth as ever, though that small tail of users sticking with old versions is growing ever larger. Stragglers sticking with version 10 or below total more than 1 percent of Web users. We offered some theories last month on what might be keeping them on these obsolete versions, but it's not obvious that those explanations are sufficient to account for everyone sticking with an old Chrome version.

Our numbers at Ars show just how much influence a single post can have. Safari was up 3.27 points, Firefox was down 2.96 points, and Internet Explorer was down 1.15 points. Chrome was basically unchanged, gaining 0.11 points. The cause of this huge swing? John Siracusa's Mac OS X Lion review, of course. The influx of Mac users caused by that post—and a handful of other Lion-related pieces—has given Apple's browser a huge boost. Expect normal service to be resumed next month.