Are you kidding? There are tons of Mac Computer Aided Design and Engineering programs. Of course, if you think the CAD universe consist of a single product, AutoCad, then you'll have to wait.

Take a look at this story for "irony" . . . Bill Gates living in a house designed on a . . gasp . . . Macintosh?

http://www.architosh.com/news/1999-07/0730-gateshousemac.phtml