If you've ever had to write a spec for a website or simply create a website for that matter, you've probably had to agree with the customer on which browsers will be supported. This can sometimes be noting short of a back-n-forth bartering process:

Ok, I'll do IE5 on Macs, but there's no way you're getting Opera 8 support!

Ok, so I've never said anything like that before, but you get the point — there's no real way of knowing exactly which to offer support for and which browsers to avoid. I've always found it's down to the open-minded/forward-thinkingness of the client.

Well, there is a better way. Yahoo! produce the Graded Browser Support (GBS) list and update it every quarter. This chart groups browsers in to different grades — A, C or X. A grade browsers receive full testing and support, C grade get some testing and X grade are all but ignored. Here's the A-grade support table as it stands now:

The changes are listed here. Notice IE5.5 and Firefox 1.0 for Windows no longer have A-grade support. Imagine how nice that would be if you'd already agreed with the customer to use this chart and to adopt any changes to it. You get the chance to move forward unhindered.

Next time you're deciding on what browsers to support I'd suggest using GBS. You can even go further and redefine how you'll offer support, like so:

Target Browser (A Grade):

Appears and behaves exactly as it was as intended to.

Supported Browser (C Grade):

Some functionality missing and some design discrepancy

Unsupported Browser (X Grade):

Content and limited functionality must work. Design must degrade nicely.

I've used this approach in the past and it's worked well.