The following is a brief outline of 's main features:

• Portability. runs on a large number of 64-bit host operating systems. See .

  is a so-called hosted hypervisor, sometimes referred to as a type 2 hypervisor. Whereas a bare-metal or type 1 hypervisor runs directly on the hardware, requires an existing OS to be installed. It can thus run alongside existing applications on that host.

  To a very large degree, is functionally identical on all of the host platforms, and the same file and image formats are used. This enables you to run virtual machines created on one host on another host with a different host OS. For example, you can create a virtual machine on Windows and then run it on Linux.

  In addition, virtual machines can easily be imported and exported using the Open Virtualization Format (OVF), an industry standard created for this purpose. You can even import OVFs that were created with a different virtualization software. See .

  For users of the functionality extends to exporting and importing virtual machines to and from the cloud. This simplifies development of applications and deployment to the production environment. See .

• Guest Additions: shared folders, seamless windows, 3D virtualization. The Guest Additions are software packages which can be installed inside of supported guest systems to improve their performance and to provide additional integration and communication with the host system. After installing the Guest Additions, a virtual machine will support automatic adjustment of video resolutions, seamless windows, accelerated 3D graphics and more. See .

  In particular, Guest Additions provide for shared folders, which let you access files on the host system from within a guest machine. See .

• Comprehensive hardware support. Among other features, supports the following:

  • Guest multiprocessing (SMP). can present up to 32 virtual CPUs to each virtual machine, irrespective of how many CPU cores are physically present on your host.

  • USB device support. implements a virtual USB controller and enables you to connect arbitrary USB devices to your virtual machines without having to install device-specific drivers on the host. USB support is not limited to certain device categories. See .

  • Hardware compatibility. virtualizes a vast array of virtual devices, among them many devices that are typically provided by other virtualization platforms. That includes IDE, SCSI, and SATA hard disk controllers, several virtual network cards and sound cards, virtual serial ports and an Input/Output Advanced Programmable Interrupt Controller (I/O APIC), which is found in many computer systems. This enables easy cloning of disk images from real machines and importing of third-party virtual machines into .

  • Full ACPI support. The Advanced Configuration and Power Interface (ACPI) is fully supported by . This enables easy cloning of disk images from real machines or third-party virtual machines into . With its unique ACPI power status support, can even report to ACPI-aware guest OSes the power status of the host. For mobile systems running on battery, the guest can thus enable energy saving and notify the user of the remaining power, for example in full screen modes.

  • Multiscreen resolutions. virtual machines support screen resolutions many times that of a physical screen, allowing them to be spread over a large number of screens attached to the host system.

  • Built-in iSCSI support. This unique feature enables you to connect a virtual machine directly to an iSCSI storage server without going through the host system. The VM accesses the iSCSI target directly without the extra overhead that is required for virtualizing hard disks in container files. See .

  • PXE Network boot. The integrated virtual network cards of fully support remote booting using the Preboot Execution Environment (PXE).

• Multigeneration branched snapshots. can save arbitrary snapshots of the state of the virtual machine. You can go back in time and revert the virtual machine to any such snapshot and start an alternative VM configuration from there, effectively creating a whole snapshot tree. See . You can create and delete snapshots while the virtual machine is running.

• VM groups. provides a groups feature that enables the user to organize and control virtual machines collectively, as well as individually. In addition to basic groups, it is also possible for any VM to be in more than one group, and for groups to be nested in a hierarchy. This means you can have groups of groups. In general, the operations that can be performed on groups are the same as those that can be applied to individual VMs: Start, Pause, Reset, Close (Save state, Send Shutdown, Poweroff), Discard Saved State, Show in File System, Sort.

• Clean architecture and unprecedented modularity. has an extremely modular design with well-defined internal programming interfaces and a clean separation of client and server code. This makes it easy to control it from several interfaces at once. For example, you can start a VM simply by clicking on a button in the graphical user interface and then control that machine from the command line, or even remotely. See .

  Due to its modular architecture, can also expose its full functionality and configurability through a comprehensive software development kit (SDK), which enables integration of with other software systems. See Programming Interfaces.

• Remote machine display. The VirtualBox Remote Desktop Extension (VRDE) enables high-performance remote access to any running virtual machine. This extension supports the Remote Desktop Protocol (RDP) originally built into Microsoft Windows, with special additions for full client USB support.

  The VRDE does not rely on the RDP server that is built into Microsoft Windows. Instead, the VRDE is plugged directly into the virtualization layer. As a result, it works with guest OSes other than Windows, even in text mode, and does not require application support in the virtual machine either. The VRDE is described in detail in Remote Display (VRDP Support).

  On top of this special capacity, offers you more unique features:

  • Extensible RDP authentication. already supports Winlogon on Windows and PAM on Linux and Oracle Solaris for RDP authentication. In addition, it includes an easy-to-use SDK which enables you to create arbitrary interfaces for other methods of authentication. See RDP Authentication.

  • USB over RDP. Using RDP virtual channel support, also enables you to connect arbitrary USB devices locally to a virtual machine which is running remotely on an RDP server. See Remote USB.

Note that any feature that is marked as experimental is not supported. Feedback and suggestions about such features are welcome.