In fact CATIA the most powerful design software in my opinion (although not the most popular due to cost) produced by Dassault Systems is a Mac program natively. A few years ago they hired IBM to make it Windows compatible so it would be a more viable competitor about the same time that they purchased Solidworks. Autodesk AutoCAD however is stuck on Windows as it relies on the .NET libraries and wont even work on WINE and it is the most recognized design software with its .dwg and .dxf file formats. As far as Unigraphics and other softwares are concerned i dont know about their compatibilities.