VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2. See "About VirtualBox" for an introduction.

Presently, VirtualBox runs on Windows, Linux, Macintosh, and Solaris hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7, Windows 8), DOS/Windows 3.x, Linux (2.4, 2.6 and 3.x), Solaris and OpenSolaris, OS/2, and OpenBSD.

VirtualBox is being actively developed with frequent releases and has an ever growing list of features, supported guest operating systems and platforms it runs on. VirtualBox is a community effort backed by a dedicated company: everyone is encouraged to contribute while Oracle ensures the product always meets professional quality criteria.

Some of the features of VirtualBox are:
* Modularity. VirtualBox has an extremely modular design with well-defined internal programming interfaces and a client/server design. This makes it easy to control it from several interfaces at once: for example, you can start a virtual machine in a typical virtual machine GUI and then control that machine from the command line, or possibly remotely. VirtualBox also comes with a full Software Development Kit: even though it is Open Source Software, you don't have to hack the source to write a new interface for VirtualBox.
* Virtual machine descriptions in XML. The configuration settings of virtual machines are stored entirely in XML and are independent of the local machines. Virtual machine definitions can therefore easily be ported to other computers.
* Guest Additions for Windows and Linux. VirtualBox has special software that can be installed inside Windows and Linux virtual machines to improve performance and make integration much more seamless. Among the features provided by these Guest Additions are mouse pointer integration and arbitrary screen solutions (e.g. by resizing the guest window).
* Shared folders. Like many other virtualization solutions, for easy data exchange between hosts and guests, VirtualBox allows for declaring certain host directories as "shared folders", which can then be accessed from within virtual machines.
A number of extra features:
* Virtual USB Controllers. VirtualBox implements a virtual USB controller and allows you to connect arbitrary USB devices to your virtual machines without having to install device specific drivers on the host.
* Remote Desktop Protocol. Unlike any other virtualization software, VirtualBox fully supports the standard Remote Desktop Protocol (RDP). A virtual machine can act as an RDP server, allowing you to "run" the virtual machine remotely on some thin client that merely displays the RDP data.
* USB over RDP. With this unique feature, a virtual machine that acts as an RDP server can still access arbitrary USB devices that are connected on the RDP client. This way, a powerful server machine can virtualize a lot of thin clients that merely need to display RDP data and have USB devices plugged in.

VirtualBox 4.3.18 (released 2014-10-10)
This is a maintenance release. The following items were fixed and/or added:
VMM: fixed a potential misbehavior after restoring the A20 state from a saved state
GUI: fixed full-screen mode mini-toolbar related regressions for different platforms and window managers (bug #13369)
GUI: X11: fixed full-screen mode Unity panels quirk caused by mini-toolbar code changes in last release (bug #13365)
GUI: X11: added possibility to use legacy full-screen mode as the new one can cause multi-screen issues under Unity, see the manual for more information (bug #13365)
GUI: Mac OS X: fixed full-screen mode artifact causing black screen when 3D acceleration was enabled on 10.10 Yosemite hosts (bug #13448)
GUI: Mac OS X: fixed regression in user-space swiping from/to VBox in full-screen mode
GUI: Mac OS X: fixed issue with switching to VBox in full-screen mode through Alt+Tab and Mission Control
Storage: fixed data corruption when resizing huge VHD images under certain circumstances (bug #11960)
Storage: fixed a rare hang during startup when the BIOS enumerates the storage devices attached to the SATA controller
Storage: follow the spec with AHCI interrupt acknowledge (bug #13474)
Storage: fixed broken iSCSI authentication (4.3.14 regression, bugs #13386, #13435)
NAT Network: properly parse port forwarding rules to allow UDP rules
USB: fixed a crash on Linux hosts with older Linux kernels (bug #13400) and several other fixes
ACPI: fixed ACPI timer anomalies (bug #12076)
Guest Control: fixed a memory leak (bug #13434)
Main: when removing a VM, do also remove the VBoxStartup.log file which might exist on Windows hosts (bug #13478)
Windows hosts: fixed more startup problems on certain Windows hosts due to conflicts with anti-virus software; better error reporting (4.3.14 regression; bug #13187)
Windows hosts: propagate the process startup information to the child process (4.3.14 regression; bug #13243)
Mac OS X hosts: don't force using the discrete GPU (bug #11111)
Windows Additions: some Windows 10 tweaks
X11 guests: fix a bug handling video driver display properties which prevented GNOME Shell on Fedora 21 from starting
Linux hosts / guests: fixed a few remaining warnings in the kernel log if memory allocation fails (bug #11171)