IE8 Passes Acid2: Believe It or Not, Microsoft Just Made Your Case

File under sentences we did not expect to write in 2007: Internet Explorer’s next version renders the Acid2 standards test correctly, and Microsoft announced it proudly, on its own blog, two days ago.

The browser that taught a generation of developers to swear is publicly measuring itself against the web-standards community’s own scorecard. Let’s savor that for a paragraph before analyzing it, because some milestones deserve the pause.

What Acid2 actually is

For readers who do not collect rendering trivia: Acid2 is a deliberately brutal test page assembled by the Web Standards Project in 2005. It is a gauntlet of CSS edge cases, error-handling requirements, and layout torture. If and only if a browser handles everything correctly, it renders as a simple smiley face.

Get anything wrong and the face arrives scrambled. Features migrate, colors bleed, the smile dissolves into modern art. It is a compliance test with a public scoreboard. Safari passed first in 2005, then Opera, then Firefox’s development builds this year. IE6 renders it as abstract expressionism. IE7, for all its real improvements, still fails it.

The test’s genius was social, not technical. ‘Supports CSS 2.1’ is a claim buried in documentation. A scrambled smiley face is a demonstration anyone can witness. The Web Standards Project built a shame mechanism disguised as a test page, and it worked. On December 19, Microsoft’s IE team posted that an internal IE8 build renders the face correctly, framing it explicitly as evidence of their commitment to interoperability.

Why Microsoft moved

Credit where due, and analysis where warranted. The competitive explanation is straightforward. Firefox has taken meaningful share. The one-in-eight visitor of last year is now pushing higher on many sites we measure. It got there partly by making standards support a selling point to the developers who influence everyone else’s defaults.

Browsers compete again, and standards compliance turned out to be a competitive feature. There is also an institutional story. The IE team that shipped IE7 talked openly about the pain of its own legacy. Passing Acid2 requires exactly the kind of ground-up rendering work that says the investment is real, not cosmetic. Whatever the mix of motives, the direction is unambiguous. And direction from the browser with the largest install base moves the whole web.

The tension IE8 will have to resolve

One engineering reality deserves a flag before anyone celebrates too cleanly. IE’s greatest asset and burden is the same thing: an enormous installed base of content built for its bugs. Intranets, enterprise applications, and yes, the hack-laden sites we have spent two years helping readers clean up.

A truly standards-compliant IE8 will render some of that legacy content differently. From its owners’ perspective, that means ‘break’ it. How Microsoft threads this is the open question of 2008. Compatibility modes, opt-in switches, or something cleverer: nobody outside Redmond knows. We would expect some mechanism that lets old content keep old behavior. The details will matter enormously to enterprise IT, and we will cover them when they are real.

Timing caveat, standard issue. IE8 has no announced ship date, and an internal build passing a test is not a product in users’ hands. IE6, now six years old, still sits on a stubborn share of institutional desktops and will for years. Nothing about today’s news retires your testing matrix. Our tiered support-policy advice from launch week stands unamended.

What the smiley face doesn’t measure

Keep the milestone in proportion. Acid2 tests a specific slice of CSS and error handling, and passing it is necessary rather than sufficient for the browser we actually want.

Outside the test’s borders lie the frontiers that will define the next few years. JavaScript performance, where the gap between engines is becoming the gap between sluggish and fluid web applications. The CSS3 features creeping into other engines as drafts mature. And the WHATWG’s work on evolving HTML itself toward application needs, with native audio and video among the ambitions. No current test page measures that, and every future site will care about it.

IE8 passing Acid2 tells us Microsoft is doing the foundational rendering work honestly. It does not yet tell us whether IE8 will be a modern browser or merely a compliant one. The distinction matters, and 2008’s builds will reveal which we are getting.

For enterprise readers, a preparatory note with a shelf life. If your organization runs internal applications certified against specific IE versions, and most large ones do, start asking vendors now where they stand. The intranet apps hard-wired to IE6’s quirks are gathering migration debt with every browser release, and ‘we require IE6’ is aging from policy into liability. The public web’s standards convergence will eventually knock on the intranet’s door. The organizations that answer early get to choose their timing.

What it means for the people who pay for websites

The budget math, since that is who we ultimately write for. Every estimate this agency has produced since founding carries an invisible line item. Call it the cross-browser tax: hours spent making one codebase behave across engines with different opinions.

That tax has been falling since IE7 shipped, and today’s announcement says it keeps falling. The market’s biggest vendor has committed, publicly and testably, to the same rules as everyone else. Convergence means correct code increasingly just works everywhere. More of every budget goes to features, content, and craft instead of compatibility archaeology.

It also validates the bet we made in March 2006. Standards-based builds were always the wager that browsers would converge on the specification rather than on each other’s bugs. Two years of evidence now runs one direction: IE7’s improvements, Firefox’s rise, WebKit spreading into pockets, and now the smiley face. Sites built to standards keep inheriting each convergence for free. Sites built to bugs keep paying rent on them.

A fine note to close the year on. The era of coding around one browser’s defiance is winding down. Not finished, but visibly, measurably ending. We will test the real IE8 whenever it arrives, report what survives contact, and keep the conditional-comment stylesheets warm in the meantime. See you in 2008. We expect an interesting year.