The Acid Test is a webs standards test to which browsers can be subjected to see which is best. Here are some of the current results for browsers that are released (the one you are likely to use if your software is reasonably well updated):
Konqueror on Ubuntu 7.10: 62%
Epiphany on Ubuntu 8.04: 59%
Camino on a Mac and Firefox on Mac, Windows XP, or Windows Vista: 52%
The list that I’m looking at then has fourteen combinations of different browsers, versions, and operating systems ranging from 39% to 52%
Then, way down the list, we get:
INternet Exporer 5.50 on Windows XP at 14%
Then a bunch of combinations of IE and various windows versions ranging from 11 to 14%.
So, we may conclude the following:
1) The operating systems that run Mac and Linux boxes (which are, from the broad perspective, very similar under the hood) are substantially better than the operating systems supplied by Microsoft for Browsing. Of course, who does browsing? Well, actually, for many it is the main thing you do… or second place, anyway.
2) The Microsoft paradigm of pretending that the browser is part of the operating system may be a useful legal ploy (well, not that useful it turns out) but it does not appear to be a good design feature, or at least, the browser that emerges from that philosophy sucks.
3) Ubuntu Linux kicks ass.
I got this information from this post, which is frequently updated.