Doesn't putting the browser in IE8 compatibility mode work? I guess it sucks for an end user to need to use a developer feature like this but could be the best option.
All the owners of the site would need to do is add this line to their HTML and it throws IE9 and later into IE8 compatibility mode:
I was surprised to notice that the BBC website does this. I noticed because a bookmarklet I wrote which requires IE9 won't work on the BBC site, which was quite disappointing.
Having done the equivalent for a gnarly enterprise web-app when IE8 came out (using mod_headers to inject the HTTP header equivalent) this isn't trivial and they may not have anyone with the necessary skills who is jumping to take on testing and support (everything which happens with that app for the next 6 months will be first blamed as an upgrade problem).
Beyond that, it doesn't actually work: some features won't be completely compatible so you're effectively creating a third browser to test and support. In the case of IE8, it was mostly IE7-compatible but it relied on the browser not throwing errors when JavaScript attempted to set syntactically invalid styles and IE8-in-IE7 still raised exceptions deep in a third-party library licensed by the app vendor. This app was made by a very large, wealthy company – we were paying mid-six-figures a year for "support" – and they preferred infrequent massive update releases, which meant that a week after I reported the bug (around the time Microsoft started pushing IE8 as an automatic install) one of their managers contacted us asking for the patch I wrote so they could redistribute it to other customers.
All the owners of the site would need to do is add this line to their HTML
No.
If they're in a situation like this, it's incredibly unlikely that anyone has the knowledge necessary to do this, let alone the time, inclination, or (perhaps most importantly for enterprise companies) business approval. The vast majority of enterprises cannot just publish production code at their own discretion.
All the owners of the site would need to do is add this line to their HTML and it throws IE9 and later into IE8 compatibility mode:
<meta http-equiv="X-UA-Compatible" content="IE=8" />
I was surprised to notice that the BBC website does this. I noticed because a bookmarklet I wrote which requires IE9 won't work on the BBC site, which was quite disappointing.