For your information, on http://www.musingsfrommars.org/2006/04/nothing-to-cheer-here-microsoft-atlas.html they've tested how cross browser the toolkit is. You can see for each component if it works in firefox, opera or safari, which may be useful for you to know.

Unfortunately the article is very negative about the toolkit, even though the Atlas Toolkit website explicitly mentions that this toolkit is an early preview. 

I wrote a blog post on Safari compat earlier this week:

http://blogs.msdn.com/sburke/archive/2006/04/17/577817.aspx

As you've pointed out, it's a preview release, which means there are lots of issue to work through, some around cross-browser compat, some not.  The posting you mention above chooses to focus very narrowly on compat issues with the first release of the Toolkit, however.

Knowing that you're working on the compat files so I'm not omplaining ... http://www.musingsfrommars.org/2006/04/nothing-to-cheer-here-microsoft-atlas.html has a list of the controls and where they are currently working (according to the author).

- Joel

hate to say this but that guy should just dump his MAC OS and get a PC... seriously who cares if <5% people can't view something. There is no way to support every broken down os/browser out there.