Internet Explorer 7 has arrived

Internet Explorer 7 has finally arrived. After years of watching Firefox, Safari and assorted other browsers discover exciting modern concepts like standards, Microsoft has released the final version of IE7. And to give credit where it’s due, it’s considerably better than those early CTP versions that occasionally felt less like software and more like an elaborate practical joke.

Compared to IE6, we now get RSS support, proper page zooming instead of merely making the text bigger, a faster JScript engine and various other features one might reasonably expect from a modern browser.

For web developers, however, the interesting part is CSS. Microsoft has implemented large chunks of CSS 2.1, added alpha transparency for PNG images and removed several of the infamous bugs and hacks that have kept frontend developers muttering obscenities at their monitors for the better part of this decade. Things are looking surprisingly good.

Not perfect, obviously. This is still Internet Explorer. There are strange behaviors lurking in dark corners, waiting patiently for the exact combination of markup and CSS that will ruin your afternoon. The CSS support still isn’t at the level of Firefox, but it’s a substantial improvement. The box model has finally been updated to behave according to the CSS 2.1 specification, a sentence that shouldn’t feel quite as exciting as it does.

IE7 also continues to support quirks mode, which means the vast graveyard of old websites held together with browser hacks and duct tape should continue functioning. Mostly.

Unfortunately, you can’t throw away your IE hacks just yet. If you need different stylesheets for different versions of Internet Explorer, conditional comments remain the least unpleasant weapon available:

And don’t expect IE6 to disappear overnight just because its younger, better-dressed sibling has walked into the room. Plenty of users will remain on IE6 long after Microsoft starts pushing IE7 through Windows Update. Corporate desktops in particular have a remarkable ability to preserve obsolete software with the determination normally associated with archaeological sites.

For developers who need to test both IE6 and IE7, things get slightly awkward. One option is to install IE7, which replaces IE6, and then install a standalone version of IE6 from evolt.org. This works more or less, although conditional comments can become confused because the standalone IE6 may believe it’s actually IE7. Because apparently even Internet Explorer suffers from identity problems. The cleaner alternative is to run IE6 inside a virtual machine. It takes a little more effort, but at least you know what you’re testing.

So here we are. IE7 is finally out. CSS support is dramatically better. PNG transparency works. The box model behaves itself. Standards support has taken a sizeable step forward. For web developers, this is unquestionably good news. Just don’t delete that IE6 stylesheet yet. The old bastard isn’t dead.