Sun VirtualBox

VirtualBox is a general purpose full virtualizer for x86 hardware. VirtualBox was developed by Sun Microsystems Inc and is distributed free of charge.

VirtualBox will basically run any operating system. The source code as well as the SDK (Software Developer Kit) has been made available for public download on the VirtualBox web site. Compiled binaries for common operating systems such as Windows, Solaris, OS X, and Linux have also been made available for download on the VirtualBox site.

For those familiar with Parallels, virtualization software designed for the Mac OS, VirtualBox is essentially a FREE alternative to Parallels. Boasting many, if not all, of the same features, it's hard to imagine why anyone would pay for Parallels when VirtualBox has been made readily available free of charge.

One of the cooler features is the "seamless mode." Which, if you are familiar with Parallels, you are more than likely familiar with this option of integrating a virtual operating system into the primary operating systems environment, creating a seamless effect in which you can't tell where one operating system ends and the other begins. Forget the old fashioned windowed virtual environment, unless of course, that is what you prefer. With seamless mode, two have become one. For more information, visit the VirtualBox web site.

OS X running Windows XP in Seamless Mode: