Steven Sinofsky, Microsoft's president of Windows and Windows Live, acknowledged that Microsoft had catching up to do. "We know we have a lot of work to do in some areas of performance," Sinofsky said at the Professional Developers Conference (PDC).
"We're getting very close to the other browsers," said Sinofsky.
The news came as no surprise to Asa Dotzler, Mozilla's director of community development, who predicted that Microsoft would tout performance gains in its next iteration of IE.
Today, Sinofsky seemed to be dumping that stance, and instead bragged not only how much faster IE9 would be, but also that its Acid3 score had improved. "We need to do a better job on Acid3," Sinofsky admitted. "We have made some improvements in IE9, which now scores 32 out of 100." IE8, he said, scored 24 out of a possible 100.
The Acid3 benchmark checks how closely a browser follows certain standards, particularly specifications for Web 2.0 applications, as well as standards related to DOM (Document Object Model), CSS2 (Cascading Style Sheets) and SVG (Scalable Vector Graphics).
Other browsers, however, have long been able to max out on the Acid3 test. Current builds of Chrome, Safari and Opera all score 100, while Firefox 3.6, which is still in beta, makes it to 92 out of 100.
Sinofsky did not talk about a release schedule for IE9, or when a public preview would be available - killing rumours that had circulated earlier this week that Microsoft might issue an early build to PDC attendees - saying that the new browser had been in development only for the "last three weeks, since we released Windows 7."