Yikes.
I'm seeing X-UA-Compatible abuse everywhere these days. It seems most of the big sites I look at have decided not to give the IE8 team half a chance to iron out their bugs, they've all simply decided to close their eyes and slap on a "behave like IE7" instruction instead. Guess if this is going to cause compat problems down the road when all non-IE browsers are forced to look at the META tags and figure out if they should be bug-compatible with IE7, 8 or 9 for any given site.. 😦
Here's a funny offender: adobe.com insists that if I'm going to show their "flashAbout_info_small.swf" animation correctly, then ..
GET /swf/software/flash/about/flashAbout_info_small.swf HTTP/1.0
Host: http://www.adobe.com
Referer: http://www.adobe.com/products/flash/about/
HTTP/1.1 200 OK
X-UA-Compatible: IE=7
Content-Type: application/x-shockwave-flash
Date: Sat, 21 Feb 2009 23:39:33 GMT
Content-Length: 594
… I have to render the .swf like IE7 would.
No problems, Adobe. Since I work for a browser vendor the server's wish should be my command. Here's your about Flash SWF rendered by IE in IE7 compat mode:
Beautifully compatible, no? Thanks for the X-UA-Compatible hint, I would never have figured that out on my own!
miscoded 
so that is what X-UA-Compatible is about, making IE look like cr@p on the webSo is the IE team's goal discrimination against other browser vendors?Very cool about Flash page, that would be easier on the eyes of older people
X-UA-Compatible should simply not be used on the web; it's a nice feature for companies that are still running webapps that depend on old IE-behaviour, but for public websites it doesn't make sense…
I don't think X-UA-Compatible is going to be a problem. It will only become a problem in browsers that implement it. So far, that's a list of one.
@Andrew: True. If one of the others breaks, though, we're all doomed.
Anonymous writes:
So Adobe has added the tag to the Apache or IIS headerinformation.Shocking.That is an efficient solution.Adobe has tested its site against IE7 and now does not have to put in the effort needed for testing IE8 compatiblity. They can hold that off untill they release a newer version fo their site. Much more efficient than testing and correcting the current version.
Not really shocking, but seeing Adobe tell the Flash player to behave like IE7 is quite funny :)Anyway, I hope Microsoft tests websites in special IE8 builds that do not respect the X-UA-Compatible tag. Otherwise, we risk IE8 bugs and compat-problems go unnoticed because the sites that would have exposed them forced IE to use IE7 rendering..
hallvors isn't the IE7 rendering engine way behind on the current technology on the web? like CSS3 and HTML 5 support?
great title. lolgood laugh for me…
Define "current".If you by "current" mean "what is used on the web today", the answer is no because the content out there is carefully tuned to the support and quirks of IE 6 and 7.If you by "current" mean "what standards say and how we would like things to be to make web development simpler and more powerful" the answer is yes. The problem is that by improving themselves they break a huge number of sites that rely on IE6-7 quirkyness and standards violations.
@crispI am not so sure that it is going to be such a "nice" feature for those using old Web designs. IE7 Compatability mode is not completely compatible with IE7. See http://www.isolani.co.uk/blog/standards/TheIe8BlacklistMinefield.
@Turin: indeed, which only shows that this 'compatibility mode' isn't a viable solution *at all*, especially not in the long term because having multiple rendermodes in one browser (adding one with each new version) simply isn't maintainable. Companies still need to test their intranet apps against specific rendermodes in a new version of IE, and when that "works" they have only bought themselves a little extra time.I still believe this problem could have been tackled more effectively if Microsoft would have made a seperate installable application of IE7 and renamed it to "Intranet Explorer" 😛
Hallvord,What's the difference between IE=EmulateIE7 and IE=7?I couldn't figure out that.
Don't really know, where did you see the EmulateIE7 syntax?
zibin are you tlaking about the thing in web pages that tell IE 8 to emulate like IE 7?
Chas4, yeaps that's what I am talking about.According to the MSDN blog, it says that IE=7 , display in IE7 Standards ModeIE=EmulateIE7, Display Standards Doctype in Standards Mode, Display quirk DOCTYPE in quirks mode.Which means IE=EmulateIE7 gives the room for certain pages in a site to have quirks mode diplay when specified while when not specified the pages will gof for IE=7 standards mode.http://blogs.msdn.com/ie/archive/2008/06/10/introducing-ie-emulateie7.aspx
Does the X-Talisman-Compatible header make Opera render things in 1995‐era 3D?http://en.wikipedia.org/wiki/Microsoft_Talisman
No, that would be X-MS-Talisman-Compatible :-p