VirtualBox 5.0.20 r106931 Final + Extension Pack

VirtualBoxVirtualBox:
is an application installed on an existing
host operating system; within this application,
additional operating systems can be loaded and run,
each with its own virtual environment. For example,
several Linux distributions can be hosted on a single
machine running Windows XP; likewise, XP and Vista
can run on a machine running Linux, and so on.
There is a free for personal or evaluation use
proprietary version and a GNU General Public License (GPL) version.

Features:
Modularity
Virtual machine descriptions in XML
Guest Additions for Windows and Linux
Shared folders
Virtual USB Controllers
Remote Desktop Protocol
USB over RDP