Why do dev tools offer Quirks mode?

Question

I'm wondering if anyone has a rationale for why web development plugins for browsers offer buttons to display content in quirks mode?

Are there people out there that markup for quirks mode on purpose? What's the point of seeing how a site will display in quirks mode when the markup already has a doc-type?

Am I missing something here or is my suspicion right that there's been a bit of wasted time here by the, might I add, excellent lads and ladettes who put these tools together?

Cheers, Steve

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EDIT: I just want to make it clear that this is a serious question. I'm not wanting to be clever. I'm seriously concerned that I'm missing the point here on something.

Answer 1

Not every web-developer has the time, skills or commitment to make everything pass W3C (afaik, google doesn't either :) ). Also, if Mr. Soccer-club computer wiz decides to make a homepage for his team, it might be easier to just make sure everything looks fine in quirks-mode, rather than parsing W3C and then do various hacks to make sure everything looks fine in all browsers..

Well, my 2 cents anyway :)

Answer 2

If you wrote a plugin for people's websites, and you happened to know that a significant number of those people use quirks mode, wouldn't you consider it a feature of your plugins to be able to use quirks mode as well?

Answer 3

Sometimes you do intend for a site to display in quirks mode. It could involve some (Crappy) legacy HTML constructs that only work in quirks mode. Or it could be pulling dirty HTML from some other source (or even shudder from users)

Also, it's pretty easy to end up in quirks mode by accident on a real complex site. Be nice to know that it doesn't totally explode

Answer 4

That feature exists primarily to test for graceful degradation on (very) old browsers such as IE5 and NS4. These browsers don't support anything like modern "standards mode", but quirks mode exists specifically to emulate their rendering style, for the purposes of being able to display as intended web pages which originally targeted those browsers.

That also makes quirks mode useful for checking how your modern, validating pages would look in those older browsers, as you may not actually have one handy to test in directly. Using a plugin to selectively toggle quirks mode makes such tests much easier than having to edit the source files; you can even check a live site.

Whether or not you feel it's worth supporting such old browsers at all, and how much effort you'll put into doing so, depends a lot on your target audience. Most of us more-or-less disregard everything older than IE6, and so won't care about quirks mode testing.

Answer 5

newer browsers like IE 6+ have their normal rendering mode for modernly coded webpages, and quirks mode to render the millions of webpages coded with methods that are now obsolete. IE looks for certain things in a webpage to see if it should switch to quirks mode to better render the page.

However, older browsers always render in "quirks" mode. (older browsers render like they do, newer browsers have quirks mode to emulate them, quirks mode wasn't around until the newer browsers needed a way to emulate the older browsers.) So if you want to get a quick idea of how a page will look in an older browser, just check it out in quirks mode in a newer one.

Answer 6

Using DocType to set standards mode is not completely reliable, unfortunately, and you don't have to go back in versions very far to find it. IE6 is one of the obvious ones, but then there are all the released versions of Mozilla/FireFox, Opera, Safari, etc etc.

Having such an option will show you what happens if the DocType switching fails, for some reason.