VirtualBox v4.1 Beta 2 is released. VirtualBox is a general-purpose full virtualizer for x86/x64 hardware. Targeted at server, desktop and embedded use, it is now the only professional-quality virtualization solution that is also Open Source Software.

VirtualBox v4.1 Beta 2 Changelog:

VMM: fixed a Beta 1 regression which prevented certain guests from booting VMM: better out-of-memory error reporting under certain circumstances GUI: display CPU cap in the VM details page WDDM: serveral fixes Storage: fixed possible data corruption under certain circumstances with VHD and Parallels images Storage: introduced non-rotational flag for hard disks for optimizing the performance with modern guests (e.g. Windows 7 will not automatically defrag the disk) Floppy: make unmounting a host floppy disk work Guest control execution: fixed documentation + syntax diagram. Solaris hosts: Host-only/Bridged networking fixes Solaris guests: fixed automounting of shared folders Linux installer: fixed compilation of the vboxpci module if DKMS is not installed Windows Installer: fixed automated VBox Python API installation. Windows hosts: fixed a BSOD in the new USB code under certain circumstances Windows hosts: use Qt 4.7.3 including Oracle certificate Experimental support for PCI passthrough (Linux hosts only) Sources: fixed USB 2.0 support for non-official builds Documentation fixes

Download: VirtualBox v4.1 Beta 2
Source: Here