VirtualBox is an open source x86 and AMD64 visualization software from Oracle, suitable for Home and Enterprise users. Version 4.1.22 of VirtualBox contains the following changes:

• VMM: fixed a potential host crash triggered by shutting down a VM when another VM was running (only affected 32-bit hosts and 64-bit OS X hosts, 4.1 regression, bug #9897)
• VMM: fixed a potential host crash under a high guest memory pressure (seen with Windows 8 guests)
• VMM: respect RAM preallocation while restoring saved state.
• VMM: fixed handling of task gates if VT-x/AMD-V is disabled
• Storage: fixed audio CD passthrough for certain media players
• USB: don't crash if a USB device is plugged or unplugged when saving or loading the VM state (SMP guests only)
• RTC: fixed a potential corruption of CMOS bank 1
• Mac OS X hosts: installer fixes for Leopard (4.1.20 regression)
• Windows Additions: fixed memory leak in VBoxTray (bug #10808)

To install VirtualBox in Ubuntu 12.10, open terminal and run the following commands:

gksudo gedit /etc/apt/sources.list
deb http://download.virtualbox.org/virtualbox/debian precise contrib
wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add -
sudo apt-get update
sudo apt-get install virtualbox-4.1