VirtualBox is an x86 virtualization software package, originally created by German software company innotek, now developed by Sun Microsystems as part of its Sun xVM virtualization platform. It is installed on an existing host operating system; within this application, additional operating systems, each known as a Guest OS, can be loaded and run, each with its own virtual environment. Supported host operating systems include Linux, Mac OS X, OS/2 Warp, Windows XP or Vista, and Solaris; there is also experimental port to FreeBSD.
Supported guest operating systems include DragonFlyBSD, FreeBSD, Linux, OpenBSD, OS/2 Warp, Windows and Solaris. The latest version also supports Windows 7 beta and release candidate 1. According to a 2007 survey by DesktopLinux.com, VirtualBox was the third most popular software package for running Windows programs on Linux desktops.