I upgraded to 10.4.3 today and noticed that the Safari that is bundled with it is now Acid 2 compliant.
Safari 2.0.2 passes Acid 2 test
What does that mean in plain english? It means that Safari is fully web standards compliant, putting it ahead of Firefox and way ahead of IE6 and even IE7.

I had been running a WebKit daily build that had this, but its nice to it productized into Safari 2.0.2. There’s a lot of other fixes in Safari 2.0.2, the biggest being some BIG memory leaks. I admit that I would quit and restart Safari every few days to deal with it, so this is a good development since it is probably the Mac app I use the most.

So go and update to 10.4.3 if you haven’t already. It’s worth it. But be sure to back up first!