#The following major new features were added:
- Reorganization of VirtualBox into a base package and Extension Packs;
- New settings/disk file layout for VM portability; see chapter 10.1, Where VirtualBox stores its files,

* Major rework of the GUI (now called “VirtualBox Manager”):
– Redesigned user interface with guest window preview (also for screenshots)
– New “scale” display mode with scaled guest display; see chapter 1.8.5, Resizing themachine’s window,
– Support for creating and starting .vbox desktop shortcuts (bug #1889)
– The VM list is now sortable
– Machines can now be deleted easily without a trace including snapshots and saved states, and optionally including attached disk images (bug #5511; also, VBoxManage unregistervm --delete can do the same now)
– Built-in creation of desktop file shortcuts to start VMs on double click (bug #2322)
* VMM: support more than 1.5/2 GB guest RAM on 32-bit hosts

* New virtual hardware:
– Intel ICH9 chipset with three PCI buses, PCI Express and Message Signaled Interrupts (MSI); see chapter 3.4.1, “Motherboard” tab,
– Intel HD Audio, for better support of modern guest operating systems (e.g. 64-bit Windows; bug #2785)

* Improvements to OVF support (see chapter 1.12, Importing and exporting virtual machines,
– Open Virtualization Format Archive (OVA) support
– Significant performance improvements during export and import
– Creation of the manifest file on export is optional now
– Imported disks can have formats other than VMDK

* Resource control: added support for limiting a VM’s CPU time and IO bandwidth;
* Storage: support asynchronous I/O for iSCSI, VMDK, VHD and Parallels images
* Storage: support for resizing VDI and VHD images;
* Guest Additions: support for multiple virtual screens in Linux and Solaris guests using X.Org server 1.3 and later
* Language bindings: uniform Java bindings for both local (COM/XPCOM) and remote (SOAP) invocation APIs

# Fixes -

- VMM: Enable large page support by default on 64-bit hosts (applies to nested paging only)
- VMM: fixed guru meditation when running Minix (VT-x only; bug #6557)
- VMM: fixed crash under certain circumstances (Linux hosts only, non VT-x/AMD-V mode only; bugs #4529 and #7819)
- GUI: add configuration dialog for port forwarding in NAT mode (bug #1657)
- GUI: show the guest window content on save and restore
- GUI: certain GUI warnings don’t stop the VM output anymore
- GUI: fixed black fullscreen minitoolbar on KDE4 hosts (Linux hosts only; bug #5449)
- BIOS: implemented multi-sector reading to speed up booting of certain guests (e.g. Solaris)
- Bridged networking: improved throughput by filtering out outgoing packets intended for the host before they reach the physical network (Linux hosts only; bug #7792)
- 3D support: allow use of CR_SYSTEM_GL_PATH again (bug #6864)
- 3D support: fixed various clipping/visibility issues (bugs #5659, #5794, #5848, #6018,#6187, #6570)
- 3D support: guest application stack corruption when using glGetVertexAttrib[ifd]v (bug #7395)
- 3D support: fixed OpenGL support for libMesa 7.9
- 2D Video acceleration: multimonitor support
- VRDP: fixed rare crash in multimonitor configuration
- VRDP: support for upstream audio
- Display: fixed occasional guest resize crash
- NAT: port forwarding rules can be applied at runtime
- SATA: allow to attach CD/DVD-ROM drives including passthrough (bug #7058)
- Floppy: support readonly image files, taking this as the criteria for making the medium readonly (bug #5651)
- Audio: fixed memory corruption during playback under rare circumstances
- Audio: the DirectSound backend now allows VMs to be audible when another DirectSound application is active, including another VM (bug #5578)
- EFI: support for SATA disks and CDROMs
- BIOS: reduce the stack usage of the VESA BIOS function #4F01 (Quake fix)
- OVF/OVA: fixed export of VMs with iSCSI disks
- Storage: Apple DMG image support for the virtual CD/DVD (bug #6760)
- Linux host USB support: introduced a less invasive way of accessing raw USB devices (bugs #1093, #5345, #7759)
- Guest Additions: Shared Folders now can be marked as being auto-mounted on Windows, Linux and Solaris guests Linux Additions: Shared Folders now support symbolic links (bug #818)
- Linux Additions: combined 32-bit and 64-bit additions into one file
- Windows Additions: automatic logon on Windows Vista/Windows 7 is now able to handle renamed user accounts; added various bugfixes