I found this article over on Maccentral which details all the IE 5 "bugs" on the Mac. Microsoft's relationship with the Mac is really quite interesting. There's this whole little section of the company slaving away over porting Office and IE to the only mainstream desktop competition Microsoft has, and the end results are usually Grade-A software. I'm not surprised IE 5 on Mac has a few CSS bugs. The only difference between the Mac version and the PC version (other than being completely different codebase, afaict :^D) is that these sorts of things are called "features" when they crop up in IE on Windows.

But while reading the article, the bit that really dawned on me is just how good a job the Mozilla team is doing. As I've said here before, if you find a bug in Mozilla on one platform, you're almost guaranteed to find the same bug happen in the same fashion with the same build of Mozilla on another. There's not much, "Mozilla 1.0.1 on Mac has these strange behaviours..." to worry about when you go crossplatform.

If you want to feel good about yourself as a web coder but you're still pretty lazy, make sure your pages work in IE on Windows, because that's what "everyone" uses, then make sure they work in Mozilla. Once you've done that, you'll at least have provided nearly every user of alternative platforms access if they'll bother with the download.