Here it is 2007, and still major players can't manage to support multiple browsers or create even marginally valid markup.
I tried to find something with yellowpages.com with Safari only to be told:
YELLOWPAGES.COM's default maps require your browser to be javascript-enabled.
If you are seeing this page, your browser has been identified as not javascript-enabled, or otherwise might have trouble viewing YPC's standard maps.
Lovely. I looked at the page and got disgusted by all the crap I found. First they use what appears to be Microsoft's Atlas and added a long Mozilla compatibility javascript library (which explains partially why it doesn't work on Safari). Plus I found that they included their unit testing javascript on every page. Not to mention the massive validation errors.
Maybe it would have been more honest to say: We don't care for Safari users, so get lost. That's about 15 million people. More than use Vista at the moment.
I still can't find in that morass where it decided I was unworthy. Who's to blame for this crap? I would love the opportunity to help them fix it.
Their mozilla javascript has comments like:
TODO - Needs thorough testing (especially timing related tests)
I wonder if they did any? When I tried Firefox it took almost 30 seconds for the map to show up.
Apparently they didn't read my post Steve Jobs Doesn't Put up Crap and Neither Should You.

lumpy 03/21/2007 15:25
On my PC running Windows XP, with Firefox, the map loaded in the blink of an eye.
sanjarUzbekistan 03/22/2007 04:08
Didn't work with Opera 9 either