Can I run MOSAIC on my Mac?
Yes, you can. Since Apple’s transition to Intel processors in 2006, Windows applications run beautifully on the Mac. Every new Mac qualifies, but older Macs may not. Please check your system profile in About This Mac to ensure what you need to run Windows.

To run Windows applications, do I have to run the Windows operating system?
Yes, you do. Basically, there are two ways to run Windows on your Mac:
1) Boot into Windows at startup. This dedicates 100% of the processor power to Windows and Windows applications. You can’t use Mac OS X again until you restart.
2) Use virtualisation software, which lets you run Mac OS X and Windows side by side. You can switch between them as easily as you’d switch between Mac applications.
NOTE: But you can’t run Windows without Windows—you’ll need to acquire your own copy of either Windows XP, Windows Vista or Windows 7 to use either solution.