VirtualBox is a family of powerful x86 virtualization products 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).
VirtualBox runs on Mac OS X, Windows and Linux and supports a large number of guest operating systems including but not limited to Windows, DOS/Windows 3.x, Linux (2.4 and 2.6), and OpenBSD.
What's new in this version:
Version 4.1.8 fixed VERR_MAP_FAILED during savestate under certain circumstances and stop updating the VM status icons when the VM is paused.