Feature VirtualBox Parallels Workstation / Desktop VMware Fusion / Workstation / vSphere

Supported host operating systems Windows XP, 2003, Vista, 2008 Server, Windows 7, 2012 Server, Windows 8, Linux, Mac OS X, Solaris 10U5+, OpenSolaris, FreeBSD Windows XP, Vista, 7, Linux, OS X Windows 2000, XP, 2003, Vista, 7, 8, Linux (32bit and 64bit), Mac OS X

Supported guest operating systems DOS, Windows 3.1, 95, 98, NT, 2000, XP, Vista, Windows 7, Windows 8, Windows Server 2003/2008/2012, Linux, OpenBSD, FreeBSD, OS/2, Solaris, OpenSolaris, others DOS, Windows 3.1, 95, 98, NT, 2000, XP, Vista, 7, 8, Linux, OS/2 DOS, Windows 3.1, 95, 98, NT, 2000, XP, Vista, 7, 8, Linux, FreeBSD, Solaris

64bit host OS support yes yes yes

64bit guest OS support yes yes yes

Intel VT-x support (CPU virtualization extensions) yes yes yes

AMD-V support (CPU virtualization extensions) yes yes yes

Virtual network cards up to 36 up to 5 up to 4

Virtual Disk Controller IDE or SATA (up to 32 disks in a guest) or SCSI IDE (up to 4) IDE or SCSI

USB support yes yes yes

iSCSI support (VMs can directly access storage servers over iSCSI) yes no no

Serial ports up to 4 up to 4 yes

Parallel ports up to 2 up to 3 yes

CD/DVD writing yes no no

3D acceleration yes (OpenGL 1.5) no limited

Support of VMware images yes no n/a

Headless operation yes no yes

Remote VM access Integrated RDP server no limited

Remote USB support Yes, arbitrary devices no no

Seamless Windows yes yes yes

Shared Folders yes yes yes

Guest power status reporting yes no yes

API Full API, 100% scriptable no yes

Open source yes (dual licensed, some enterprise features are closed source) no no

Customizations yes, upon request no no