This version is a major update. The following major new features were added:
Following the acquisition of Sun Microsystems by Oracle Corporation, the product is now called "Oracle VM VirtualBox" and all references were changed without impacting compatibility
Experimental support for Mac OS X Server guests (see Section 3.1.1, “Mac OS X guests”)
Memory ballooning to dynamically in- or decrease the amount of RAM used by a VM (64-bit hosts only) (see Section 4.8.1, “Memory ballooning”)
Page Fusion automatically de-duplicates RAM when running similar VMs thereby increasing capacity. Currently supported for Windows guests on 64-bit hosts (see Section 4.8.2, “Page Fusion”)
CPU hot-plugging for Linux (hot-add and hot-remove) and certain Windows guests (hot-add only) (see Section 9.5, “CPU hot-plugging”)
New Hypervisor features: with both VT-x/AMD-V on 64-bit hosts, using large pages can improve performance (see Section 10.6, “Nested paging and VPIDs”); also, on VT-x, unrestricted guest execution is now supported (if nested paging is enabled with VT-x, real mode and protected mode without paging code runs faster, which mainly speeds up guest OS booting)
Support for deleting snapshots while the VM is running
Support for multi-monitor guest setups in the GUI for Windows guests (see Section 3.5, “Display settings”)
USB tablet/keyboard emulation for improved user experience if no Guest Additions are available (see Section 3.4.1, “"Motherboard" tab”)
LsiLogic SAS controller emulation (see Section 5.1, “Hard disk controllers: IDE, SATA (AHCI), SCSI, SAS”)
VRDP video acceleration (see Section 7.1.9, “VRDP video redirection”)
NAT engine configuration via API and VBoxManage
Use of host I/O cache is now configurable (see Section 5.7, “Host I/O caching”)
Guest Additions: added support for executing guest applications from the host system (replaces the automatic system preparation feature; see Section 4.7, “Guest control”)
OVF: enhanced OVF support with custom namespace to preserve settings that are not part of the base OVF standard
In addition, the following items were fixed and/or added:
VMM: fixed Windows 2000 guest crash when configured with a large amount of RAM (bug #5800)
Linux/Solaris guests: PAM module for automatic logons added
GUI: guess the OS type from the OS name when creating a new VM
GUI: added VM setting for passing the time in UTC instead of passing the local host time to the guest (bug #1310)
GUI: fixed seamless mode on secondary monitors (bugs #1322 and #1669)
GUI: offer to download the user manual in the OSE version (bug #6442)
GUI: allow to set an empty host key to disallow any host key combination (bug #684)
GUI: allow to restrict the possible actions when shutting down the VM from the GUI
Main: allow to start a VM even if a virtual DVD or floppy medium is not accessible
Settings: be more robust when saving the XML settings files
Mac OS X: rewrite of the CoreAudio driver and added support for audio input (bug #5869)
Mac OS X: external VRDP authentication module support (bug #3106)
Mac OS X: moved the realtime dock preview settings to the VM settings (no global option anymore). Use the dock menu to configure it
Mac OS X: added the VM menu to the dock menu
3D support: fixed corrupted surface rendering (bug #5695)
3D support: fixed VM crashes when using ARB_IMAGING (bug #6014)
3D support: fixed assertion when guest applications uses several windows with single OpenGL context (bug #4598)
3D support: added GL_ARB_pixel_buffer_object support
3D support: added OpenGL 2.1 support
3D support: fixed Final frame of Compiz animation not updated to the screen (Mac OS X only) (bug #4653)
3D support: fixed blank screen after loading snapshot of VM with enabled Compiz
Added support for Virtual Distributed Ethernet (VDE) (Linux hosts only; see Section 6.2, “Introduction to networking modes”)
Added support for virtual high precision event timer (HPET)
OVF: fixed mapping between two IDE channels in OVF and the one IDE controller in VirtualBox
OVF: fix VMDK format string identifiers and sort XML elements from rasd: namespace alphabetically as prescribed by standard
VBoxShell: interactive Python shell extended to be fully functional TUI for VirtualBox
Linux Additions: support Fedora 13 (bug #6370)
VBoxManage: fixed overly strict checks when creating a raw partition VMDK (bugs #688, #4438)