I just spent most of today making Don't Rush work on Windows. Of course IE was the biggest challenge, but both Firefox and Safari had issues I had to work out that didn't effect the other two browsers.

One thing struck me towards the end of the day though, and it wasn't anything about not following standards, I knew all that. The web looks dreadful on Windows. It's not IE, it's just Windows. The fonts aren't rendered as nicely, the buttons all look horrible - it's just not as pretty.