Yesterday, at the MIX08 conference, Microsoft released the first beta of Internet Explorer 8 (IE8), which is available for immediate download ( Internet Explorer 8 beta). It promises several technical enhancements-as well as several philosophical improvements. After a session demonstrating the technical underpinnings of the beta release, the initial community response was, in the words of one developer, "Sweet!"

Microsoft is swift to point out that Beta 1 is a developer release, rather than one meant for end users to test. "It's very early; we're not done," said Chris Wilson, the IE Platform Architect, during the technical breakout session introducing the new browser version. "We're not talking (yet) about the user experience." This Beta version puts its attention on security, interoperability and better programming features. Among the enhancements are CSS 2.1 support, CSS certification, performance improvements, HTML 5 support, built-in development tools, and two new user features-Activities and WebSlices-that developers will want to explore.

Renewed Commitment to Web Standards

A key change in Microsoft's plans is that-just announced this week-IE8 will default to standards-compliance mode, rather than legacy support for previous browser versions. "Compatibility is key," said Wilson.

"We will give you the best approximation of the standard that we can," said Wilson. But if you've written apps to work only with certain versions and features, all is not lost. Authors can upgrade their content when they're ready; in the meantime, they can tell the browser to use "old rendering."

Importantly, IE8 is complying more with CSS standards. "We have the goal of having full and complete support for CSS 2.1," said Wilson. "This is a big goal." To that end, IE8 has a new layout engine with a great typographic foundation that's designed with CSS 2.1 in mind, and clear principles of compliance and interoperability. "Yes, this is the end of hasLayout," said Wilson to audience applause, "Though we still have it in 'quirks mode'."

With IE expecting Web applications to conform to W3C standards, and the commitment to full CSS compliance, says author and Web standards activist Molly Holzschlag, "It will make life easier for everybody." Developers will be easier to develop, to scale, and to maintain since less time will need to be invested in making an app run in a particular browser instead of writing great software. "You won't have to train people to do things to get around IE," said Holzschlag, who also pointed out that IE6 will still be around for a long time (so the cussing will continue for a while).

Down 'n Dirty Developer Details

Security was a major issue addressed with IE7. That hasn't changed. In IE8, said Wilson, "We continue to invest heavily in security." For example, work has been done on ActiveX, to make it more targeted. "Most of the problems we've had with ActiveX is with things being misused," said Wilson, so IE8 will permit both per-user ActiveX installs without admin privileges and per-site ActiveX controls. With the latter, for example, the browser can be set to allow one site to use an ActiveX control, but not all sites. IE8 also has DEP/NX code execution prevention by default, leveraging Windows Vista, said Wilson.

Security is an element of what Wilson called "the mashup dilemma." The most interesting Web apps mashup data and components across domains-which is not safe. "I don't want anybody mashing up data from my Bank of America account!" he said. IE8 is implementing a new object to ensure that cross-domain requests require mutual consent, so that both sites okay the exchange of data. Similarly, IE8 can enforce limitations on cross-document messaging.

IE8 is also unlocking the Web for accessibility reasons, said Wilson, to support W3C ARIA specifications and make advanced Web content accessible. Many Web 2.0 and Ajax applications, explained Wilson, are hard or impossible to use when using an assistive technology like a screen reader.