Parallels.com
Parallels Desktop is the best choice for running multiple OSs on my Mac
I use Parallels Desktop to access Windows on my Mac. There are e-Learning and local government design applications that require the exclusive use of the Windows OS, and this has helped me to not need to have two computers but work on one machine with access to both operating systems. Additionally, on occasion some of my colleagues require support with their computers, and I can replicate the problems they have on the operating systems they are running in a user-friendly and very fast way.
