As you would expect, we test our web sites, applications and email templates for the most common system set ups. I thought it would be interesting to share with you some of the sources we use for this information. I know, I know - "interesting" is pushing it a bit far!
The first graphic shows the break down of browsers people are using for a "web 2.0" site we run.
The second image shows the browser breakdown on a much more "traditional" charity web site, in this case for a visual impairment charity. As you can see, the breakdown is significantly different, proving there's no such thing as an average web site or an average visitor!
If you'd like to know what browsers (and screen sizes etc etc) the visitors to your web site are using, you'll find it all in your Google analytics account at >visitors>browser capabilities>browsers.