VirtualBox consente di far girare contemporaneamente diversi sistemi operativi (Windows, Linux, ecc.) su un singolo PC, ciascuno con le proprie applicazioni.
Concorrente gratuito (open source) di VMWare, e Virtual PC di Microsoft.

Grosse novità per VirtualBox 1.40 (per dettagli, vedere il changelog):

• Among the new features are full support for 64-bit Linux hosts, RDP session shadowing, clipboard synchronization, serial ports and easier Linux host interface networking. In the storage department, VirtualBox now supports VMware disk images (VMDK) natively and can give virtual machines access to physical disks and partitions ("raw disk support"). The graphical user interface has received more polish and has now been translated into 12 languages (German, Spanish, French, Italian, Polish, Portuguese, Romanian, Arabic, Russian, Japanese, Traditional Chinese and Chinese). Red Hat Enterprise Linux 5 (RHEL5) and Xandros Desktop 4.1 are now officially supported; support for FreeBSD and OpenBSD guests has been improved.