Google Chrome and Microsoft Internet Explorer 8 were the big winners last month in the browser share sweepstakes, according to web measurement firm Net Applications.
Chrome's usage share climbed by 0.4 of a percentage point, from 1.4 percent to 1.8 percent, the largest one-month increase since the browser debuted last September. The gain represented a 27 percent surge over April.
Microsoft's newest browser also posted its biggest-ever increase, gaining 3.7 percentage points to end May at 7.6 percent - a one-month growth rate of over 91 percent - as the upgrade process rolled out to more users.
Microsoft launched IE8 in March, but didn't begin offering IE6 and IE7 users an upgrade until the third week of April. Not until May, however, did Microsoft open the Windows Update throttle for the IE8 offer.
The browser will not be pushed to corporate PCs managed by Windows Server Update Services (WSUS) until July, at which time IE8 should receive an additional bump in share.
IE8 presents a special tallying problem for Net Applications, the company said today. The trouble stems from IE8's "compatibility view" feature, which lets users display sites as rendered by the older - and often web standard-incompatible - IE7.
"This has lead to underreporting of Internet Explorer 8, since about one-fifth of IE8 browsing in our sample is done in compatibility view mode," Net Applications noted on its web site.