VirtualBox is a new, freeware virtualization software for Windows and Linux computers that supports Windows XP and Linux distros as the target OS. Support for Mac OS X and 64-bit operating systems is currently in the works.

Common features of the software include:

Modularity: You can control a virtual machine rom 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.

Virtual machine descriptions in XML: The configuration settings of virtual machines are stored in the common XML format and are independent of the local machines. Virtual machine definitions can therefore easily be ported/used on other computers.

Guest Additions for Windows and Linux: VirtualBox provides addon software (similiar to what Virtual PC and VMWare provide) that can be installed inside Windows and Linux virtual machines to improve performance of the virtual machine. Among the features provided by these Guest Additions are mouse pointer integration and arbitrary screen solutions (e.g. by resizing the guest window).

There are two versions of the software- an open source version which can be used for free and a closed source version which provides additional features such as:

-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.
-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.

The closed source version is free but only for personal use, not for commercial/business purpose.

Download the Windows version here

Other Linux distro versions including Bittorrent downloads for Windows and Linux versions can be downloaded from here

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