Originally posted by danielctullAnd even given all of Firefox's pros, it still isn't fully standards compatible. Safari is the only browser to pass the Acid2 test.
I was flicking through a Linux magazine and caught sight of the face and read the little snippet. They were comparing how different browsers showed the face. IE failing, Firefox not so much, but still failing. For some reason they didn't show how Safari did...
The Acid2 test really isn't very significant to web designers since it's testing mostly how some evilly convoluted CSS fails in an appropriate way. Most of the standards it addresses are future standards that aren't used today. It's become a cause célèbre amongst geeks and web browser developers but it's importance is minimal for designers. It just shows that the developers care about standards more than anything else.
Firefox and Safari are close enough with web standards compliance to almost not bother testing one or the other provided you keep within compliant code. 99.9% of the time a website designed in Safari will be identical in Firefox. And if they aren't identical you know at least you can raise a bugzilla report and have it fixed.
The differences mostly come down to IE compatibility. Both Firefox and Safari are encumbered with the entirely pragmatic approach of having to present pages 'just like IE' in the event they are given badly designed pages and it's there that they differ. They do this because if they didn't, dumb people would just presume the browser was broken, not the website, and go back to using IE. IE did the web a huge disservice by being extremely slack in allowing any old crap to render and now we have to support those old sites that work just fine on IE by introducing the same support for bad sites in other browsers.
However, if you come across a site that doesn't work in Firefox or Safari then please tell the web designer. Some of us do care that our work doesn't work on all browsers.