VirtualBox for Mac Download

BleepingComputer Review:

VirtualBox  is free and enterprise-ready virtual machine platform that allows you to run other operating systems within Mac OS X.  Using VirtualBox you are able to install other operating systems into a virtual computer that can be launched  and used directly within Mac OS X. This allows you to run virtually any operating system at the same time while using Mac OS X, including Windows.

When using VirtualBox, the software is installed on the host machine and then any other virtual machines are considered guests of that host. These guest virtual machines can be running a variety of different operating systems that include older versions of Windows, linux, and MacOS.  Using a program like VirtualBox allows you to perform a variety of tasks from a single computer such as testing operating systems before you install them, run software that only works on older versions of Windows, analyze malware without risk of your normal machine becoming infected, and to develop software for other operating systems.  It is also useful for running servers that need to be seperated but are not resource intensive enough to require their own machine.