Microsoft’s Chris Wilson has a post on Compatibility and IE8 which introduces yet another compatibility switch. IE8 will apparently have three modes: Quirks, Standards, and Even More Standard.

Here’s the key paragraph:

… developers of many sites had worked around many of the shortcomings or outright errors in IE6, and now expected IE7 to work just like IE6. Web developers expected us, for example, to maintain our model for how content overflows its box, even in “standards mode,” even though it didn’t follow the specification – because they’d already made their content work with our model. In many cases, these sites would have worked better if they had served IE7 the same content and stylesheets they were serving when visited with a non-IE browser, but they had “fixed their content” for IE. Sites didn’t work, and users experienced problems.

In other words, so many web pages have “If IE, do this” coded into them, that pages actually break if IE behaves correctly. Alternative browsers will do a better job, even if IE is equally standards-compliant, because they do not suffer the effects of these workarounds.

Microsoft’s proposed solution is to make the supposed Standards mode a new quirks mode, this time frozen to IE7 compatibility, and to force developers to add a further meta tag to enable the better standards compliance of which IE8 is capable.

It actually goes beyond that. Aaron Gustafson explains the rationale for the new X-UA-Compatible meta tag which enables web developers to specify what browser versions their page supports. The idea seems to be that browsers parse this tag and behave accordingly.

This sounds uncomfortable to me. Versioning problems are inherently intransigent – DLL Hell, the Windows GetVersion mess – and this could get equally messy. It is also imposing a substantial burden on browser developers.

Has Microsoft made the right decision? Trouble is, there is no right decision, only a least-bad decision. Personally I think it is the wrong decision, if only because it perpetuates the problem. It would be better for IE to do the correct thing by default, and to support meta tags that turn on quirks modes of various kinds, or an option in browser preferences, rather than doing the incorrect thing by default.

Still, Wilson makes a case for the decision and has some supporters. Nevertheless, he is getting a rough ride, in part because the IE team has failed to engage with the community – note for example the long silences on the IE blog. Why is Wilson telling us now about this decision, as opposed to discussing the options more widely before it was set in stone, as I suspect it now is? Even within the Web Standards Project, some of whose members assisted Microsoft, there is tension because it it appears that other members were excluded from the discussion.

Another point which I’m sure won’t go unnoticed is that Wilson makes a good case for using alternative browsers. IE users get inferior markup.