VirtualBox v4.2 RC 3 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 v4.2 RC 3 Changelog:
Incomplete list of fixes since VirtualBox 4.2.0 RC2:
VMM: fixed handling of task gates if VT-x/AMD-V is disabled
GUI: if the user pressed cancel on restore + snapshot current, the current state was lost
GUI: a couple of VM group related fixes
GUI: fixed guest resize of maximized Windows with certain window managers (Beta1 regression)
GUI: added Devices/Shared Clipboard to enable/disable the clipboard at runtime
fixed eCS 2.1 CD installer hang/crash (Beta1 regression)
fixed somewhat rare Solaris GRUB boot errors with SATA (Beta1 regression)
Main: fixed registering of new VMs (was broken since RC2)
3D: fixed application crashes on application shutdown (RC1 regression)
CD: fixes for audio CD passthrough for certain media players
Guest Control: a couple of fixes
OS X hosts: sign binaries
Windows Additions: fixed signing of 32-bit Windows Additions (Beta1 regression)
Solaris Additions: notify the kernel mouse subsystem of virtual resolution changes in vboxvideo.

VirtualBox 4.2 will be a new major release. The following major new features were added:
Improved Windows 8 support, in particular many 3D-related fixes
GUI: VM groups (bug #288)
GUI: expert mode for wizards
GUI: allow to alter some settings during runtime
Support for up to 36 network cards, in combination with an ICH9 chipset configuration (bug #8805)
Resource control: added support for limiting network IO bandwidth; see the manual for more information
Added possibility to start VMs during system boot on Linux, OS X and Solaris; see the manual for more information (bug #950)
Added experimental support for Drag'n'drop from the host to Linux guests. Support for more guests and for guest-to-host is planned. (bug #81)
Added support for parallel port passthrough on Windows hosts
Enhanced API for controlling the guest; please see the SDK reference and API documentation for more information
In addition, the following items were fixed and/or added:
Mac OS X hosts: sign application and installer to avoid warnings on Mountain Lion
VMM: improved VM context switch performance for Intel CPUs using nested paging
VMM: added support for FlushByASID features of AMD CPUs (Bulldozer and newer)
VMM: fixed unreal mode handling on older CPUs with VT-x (gPXE, Solaris 7/8/9; bug #9941)
VMM: fixed MP tables fixes for I/O APIC interrupt routing relevant for ancient SMP guests (e.g. old OS/2 releases)
VMM: support recent VIA CPUs (bug #10005)
VMM: fixed handling of task gates if VT-x/AMD-V is disabled
GUI: network operations manager
GUI: allow taking screenshots of the current VM window content (bug #5561)
GUI: allow automatically sorting of the VM list
GUI: allow starting of headless VMs from the GUI
GUI: allow reset, shutdown and poweroff from the Manager window
GUI: allow to globally limit the maximum screen resolution for guests
GUI: show the full medium part on hovering the list of recently used ISO images
GUI: do not create additional folders when a new machine has a separator character in its name (bug #6541)
GUI: don't crash on terminate if the settings dialog is still open (bug #9973)
GUI: consider scaled DPI values when display fonts on Windows hosts (bug #9864)
Snapshots: fixed a crash when restoring an old snapshot when powering off a VM (bugs #9364, #9604, #10491)
Clipboard: disable the clipboard by default for new VMs (see the manual for more information). It can be enabled at any time using the VM menu.
Settings: sanitise the name of VM folders and settings file (bug #10549)
Settings: allow to store the iSCSI initiator secret encrypted
NAT: improvements for the built-in TFTP server (bugs #7385, #10286)
E1000: 802.1q VLAN support (bug #10429)
Storage: implemented burning of audio CDs in passthrough mode
Storage: fixed audio CD passthrough for certain media players
Storage: implemented support for discarding unused image blocks through TRIM for SATA and IDE and UNMAP for SCSI when using VDI images
Storage: added support for QED images
Storage: added support for QCOW (full support for v1 and readonly support for v2 images)
Storage: added readonly support for VHDX images
Solaris additions: added support for X.org Server 1.11 and 1.12
Solaris additions: switched to using an in-kernel mouse driver
Windows hosts: no need to recreate host-only adapters after a VirtualBox update
Windows hosts: updated toolchain; make the source code compatible to VC 2010 and enable some security-related compiler options

Download: VirtualBox v4.2 RC 3
Source: Here