IE 7 won't pass the Acid2 test

Microsoft's new Internet Explorer 7 browser won't pass a stringent standards test that rivals have embraced.

In its browser blog, Microsoft acknowledged that IE 7 would not pass the Web Standards Project's Acid2 test, which examines a browser's support for W3C (World Wide Web Consortium) recommendations including CSS1 (Cascading Style Sheets), HTML4 and PNG (Portable Network Graphics).

Chris Wilson, lead program manager for the web platform in IE, wrote in the IE blog: "We will not pass this test when IE 7 ships. We fully recognise that IE is behind the game today in CSS support.

"We've dug through the Acid2 test and analysed IE's problems with the test in some great detail, and we've made sure the bugs and features are on our list - however, there are some fairly large and difficult features to implement, and they will not all sort to the top of the stack in IE 7."

Standards advocates and web developers have criticised Microsoft for letting Internet Explorer go without a significant upgrade for years. This spring it became clear that Microsoft would finally address long-standing standards compliance issues in its planned version 7 upgrade.

Microsoft last week came out with a test, or "beta" version, of its Windows Vista operating system and IE 7.

Wilson said the broad range of Acid2's demands made it more of a "wish list" than a "compliance test".

Wilson wrote: "As a wish list, it is really important and useful to my team but it isn't even intended, in my understanding, as our priority list for IE 7."

The Web Standards Project responded positively to the announcement, hailing Microsoft's standards to-do list and its openness in acknowledging the test.

Web Standards Project member Chris Kaminski wrote: "While it doesn't hit everything we might like, and we won't see most of it until Beta 2, it's a pretty impressive list for a release that by all accounts is primarily about security and UI features.

"Even more impressive than the contents of the list, though, is that it's even available outside the Redmond campus. Having been through this 'work with Microsoft' thing once before in the late 90s, I can assure you this sort of openness is a radical departure from the Microsoft of old and as good a reason as any for optimism that this is just the beginning, and we can expect even more and better in IE 7.5 and beyond."

The Web Standards Project launched seven years ago to goad Microsoft and Netscape into heeding W3C recommendations. These days, the group takes a less confrontational approach than it used to, working closely with software companies like Macromedia and Microsoft before products are released.

Microsoft's competitors sounded a less forgiving note in responding to the news.

Hakon Lie, chief technology officer of Opera Software in Oslo, Norway, said: "I think they should take the time required to do this right. We're not going to see another IE for another several years, and this is their chance to show that they really care about standards, as they've been saying. They've used so many years to create IE 7, they can take the extra month required to make it pass."

Lie said Opera was "very close" to passing Acid2. Apple has already said its Safari browser passes the test in preliminary builds. The Mozilla Foundation said it was committed to "full support" of Acid2 in its Firefox browser but did not say when it expected to pass the test.

Paul Festa writes for CNET News.com