GemGuide Appraisal Software is a Windows or PC based software product. But you can use the appraisal software if you have any virtual machine (VM) software installed on your MAC. VM software such as Fusion or Parallels will let anyone run Windows and hundreds of other operating systems on a Mac, without rebooting. A version of Windows is required when installing the VM software on your MAC. Both Fusion and Parallels programs are supported by Apple.
The Boot Camp software provided by Apple also acts as a virtual machine on your MAC computer. It allows the Mac computer to emulate the PC so any PC based program can operate on the Mac. You will need to install a version of Windows within your Boot Camp software. The downside to this option is that you need to start the Mac computer in Boot Camp mode to use the PC mode and then restart or reboot the computer to use the Mac OS system.