Please no. The web industry has suffered enough because of IE. There's no reason for a book like this to even acknowledge it's existence. Of course I'm referring to older versions of IE. Newer ones at least support common use cases.
I'd maybe mention the use of something like Respond [1] to deal with media queries but I wouldn't go any further than that.
> There's no reason for a book like this to even acknowledge it's existence.
That's not right; of course there's are reasons, though you're welcome to debate how much weight those reasons have.
I don't know what percentage of sites have a business need to support old IE versions.
I know we do -- our site is used by medical staff in hospitals where the PCs are locked-down, upgrades are hugely expensive and difficult (the silent auto-upgrade approach just isn't safe), and so even though no one likes IE7 there are still plenty of hospitals who haven't yet succeeded in upgrading.
There are other industries besides healthcare that suffer from this effect as well -- think especially of cases where companies have paid serious money for custom-developed systems that were cutting-edge in 1999, and thus were fully-browser-based and used the leading browser technology at the time, which was IE 5 with a ton of ActiveX (or Java applets?). If they still fill the business need perfectly well, the options around upgrading are not at all clear-cut.
I'm not sure how big this need is; I'm obviously biased because it affects me directly.
It's the sort of question that needs more data than just what I think about it.
But for a gut feeling -- no, not at all. No one wants to support old browsers, and if you pay for custom site development, it's a common practice to add seriously high extra fees if that's a requirement.
And so most sites don't support them.
But all of this doesn't really encourage or discourage a business that has really poor options around upgrading. In some ways it's just irrelevant; they're using the browser as a tool for employees to complete specific tasks, and if Facebook doesn't work (but the expensive internal tools do) that's just fine.
The two domains collide when there are new, external tools that are introduced to the environment. ...and this is why we need some support of old IE, because we really don't want our sales pitch to include "...but you'll need to also spend untold amounts of cash and effort to upgrade your browsers, first".
Please no. The web industry has suffered enough because of IE. There's no reason for a book like this to even acknowledge it's existence. Of course I'm referring to older versions of IE. Newer ones at least support common use cases.
I'd maybe mention the use of something like Respond [1] to deal with media queries but I wouldn't go any further than that.
1. https://github.com/scottjehl/Respond