Which Browsers must a site work with

Thanks for the sugestion Nareau, but I discounted that approach because the proportion of visitors wth JS dissabled is increasing all the time. This is likely to increase even further in the light of recent IIS hacking exploitations using JS to infect visitors.

This solution is excelent when it works, but when a visitor with a non JS browser visits, the wheels fall off.

In addition, a visitor with a NN4.x browser who turns off JS also efectively runs with no CSS. For me that is an awesome challenge.

I always use @import with CSS so that older browsers do not see any CSS at all.
No challenge at all. They get lightning fast, but unstyled, content.

IMHO a website should be seen in the major ones that your visitors use.
For example, I have a website that is seen 80% by Internet Explorer, 7% by Opera and 5% by Mozilla (Firefox included). So, I make sure that my website is seen the way i've designed it in that browser...

Currently I have instaled on my machine the following

- Internet Explorer
- Mozilla Firefox
- Opera
- Netscape (the same as Mozilla)
- Mozilla

Anyway, design your websites to your users, not to Search Engines, Spiders or DMOZ editors (even those are "normal" Internet users). Just think this way, if Seach Engines or ODP doesn't exist would you do that? If not, don't do it, do what your visitors want or need