These days is it required to test a desktop website for IE6 and IE7? Or is IE8 and IE9 enough?
I heard that IE8 has replaced IE7.
You need to consider your where your target audience is from.
For example, looking at the United Kingdom:
Results: 1.72% IE6, and 6.66% IE7.
So for websites designed for UK businesses targeting UK clients, I feel safe dropping IE6. I try to make it work in IE7 where possible, but it's fine if it's not perfect. It's much the same story for America.
On the other hand, if you're looking at India:
Results: 11.81% IE6, and 5.33% IE7.
IE6 actually has higher usage than IE7. I can't comment on India, but those statistics don't look good.
China makes me cry:
Results: 40.54% IE6, and 5.64% IE7.
Results: 3.84% IE6, and 6.39% IE7.
Look at your own web analytics stats (You do have analytics, right?). That'll tell you how many IE6 users you have. Then make a business decision.
See Internet Explorer Browser Statistics. Personally, I think you should not care anymore of IE6: those users háve to upgrade, and this is one way to reach that. I would care for the 5% IE7 is still scoring though.
According to our Firestats (web statistic tool) and various statistics on the internet, there is a significant number of ie6 users out there. so if you want to satisfy every single user, you should test for ie6 too. microsoft itself discourages the use of ie6. they also have a website with the sole purpose to reduce the number of ie6 users (link)
dont know about ie7 though, but in terms of website development there are only small differences between ie6 and ie7
If your web site is a public facing site, then you could use whatever web stats (e.g. Google Analytics) you have in place to determine what proportion of your users are still using IE6, 7.
Alternatively, this Wikipedia page lists the market share of different versions of IE over the years. For April 2011, the figures are 2.41% for IE9, 33.06% for IE8, 7.35% for IE7 and 10.85% for IE6.
Note that these figures are not representative of overall market share, but within the share that IE has in general alongside other browsers (60% in 2010).
My brief take on this is:
In other words, try and make it usable in IE6 but don't care about rendering problems or bugs in layout. You could always use something like http://ie6update.com/ to give users a gentle warning.
I am not sure how right the following statistics is, but according to it IE6 has 10% and IE7 - 7% of browser marketshare.
It depends on numerous factors, but IE6 and IE7 totally didn't go away overnight. I'm doing a job for a big corporation at the moment, and while there's a lot of money there, the upgrade to Windows 7 (and away from IE6) is only planned to be finished in 2012.
The best way to decide if there is a current website, you can just look at the visitor stats for browser versions. Otherwise try to find a website with similar audience and with published stats to gauge how much you need to worry about legacy browsers.
I think it depends a lot on the audience the site is aimed at. If it's aimed at a developer crowd (like a vast majority of people who come to places like Stack Overflow, I would assume) then IE8 and IE9 will be fine. A lot of our clients are businesses with offices all over the place so we still have to optimise for IE6 (grrr)