VirtualBox is a free and open source, powerful, feature-rich, cross-platform and popular x86 and AMD64/Intel64 virtualization software for enterprise and home use. It is targeted at server, desktop, and embedded use.
It runs on Linux, Windows, Macintosh, and Solaris hosts and supports a large number of guest operating systems including but not limited to Linux (2.4, 2.6, 3.x and 4.x), Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7, Windows 8, Windows 10), DOS/Windows 3.x, Solaris and OpenSolaris, OS/2, and OpenBSD.