[from virtualbox.org/wiki/Changelog ]
VirtualBox 2.1.0 (released 2008-12-17)
This version is a major update. The following major new features were added:
Support for hardware virtualization (VT-x and AMD-V) on Mac OS X hosts
Support for 64-bit guests on 32-bit host operating systems (experimental; see user manual, chapter 1.6, 64-bit guests, page 16)
Added support for Intel Nehalem virtualization enhancements (EPT and VPID; see user manual, chapter 1.2, Software vs. hardware virtualization (VT-x and AMD-V), page 10))
Experimental 3D acceleration via OpenGL (see user manual, chapter 4.8, Hardware 3D acceleration (OpenGL), page 66)
Experimental LsiLogic and BusLogic SCSI controllers (see user manual, chapter 5.1, Hard disk controllers: IDE, SATA (AHCI), SCSI, page 70)
Full VMDK/VHD support including snapshots (see user manual, chapter 5.2, Disk image files (VDI, VMDK, VHD), page 72)
New NAT engine with significantly better performance, reliability and ICMP echo (ping) support (bugs #1046, #2438, #2223, #1247)
New Host Interface Networking implementations for Windows and Linux hosts with easier setup (replaces TUN/TAP on Linux and manual bridging on Windows)
In addition, the following items were fixed and/or added:
VMM: significant performance improvements for VT-x (real mode execution)
VMM: support for hardware breakpoints (VT-x and AMD-V only; bug #477)
VMM: VGA performance improvements for VT-x and AMD-V
VMM: Solaris and OpenSolaris guest performance improvements for AMD-V (Barcelona family CPUs only)
VMM: fixed guru meditation while running the Dr. Web virus scanner (software virtualization only; bug #1439)
VMM: deactivate VT-x and AMD-V when the host machine goes into suspend mode; reactivate when the host machine resumes (Windows, Mac OS X & Linux hosts; bug #1660)
VMM: fixed guest hangs when restoring VT-x or AMD-V saved states/snapshots
VMM: fixed guru meditation when executing a one byte debug instruction (VT-x only; bug #2617)
VMM: fixed guru meditation for PAE guests on non-PAE hosts (VT-x)
VMM: disallow mixing of software and hardware virtualization execution in general (bug #2404)
VMM: fixed black screen when booting OS/2 1.x (AMD-V only)
GUI: pause running VMs when the host machine goes into suspend mode (Windows & Mac OS X hosts)
GUI: resume previously paused VMs when the host machine resumes after suspend (Windows & Mac OS X hosts)
GUI: save the state of running or paused VMs when the host machine’s battery reaches critical level (Windows hosts)
GUI: properly restore the position of the selector window when running on the compiz window manager
GUI: properly restore the VM in seamless mode (2.0 regression)
GUI: warn user about non optimal memory settings
GUI: structure operating system list according to family and version for improved usability
GUI: predefined settings for QNX guests
IDE: improved ATAPI passthrough support
Networking: added support for up to 8 Ethernet adapters per VM
Networking: fixed issue where a VM could lose connectivity after a reboot
iSCSI: allow snapshot/diff creation using local VDI file
iSCSI: improved interoperability with iSCSI targets
Graphics: fixed handling of a guest video memory which is not a power of two (bug #2724)
VBoxManage: fixed bug which prevented setting up the serial port for direct device access.
VBoxManage: added support for VMDK and VHD image creation
VBoxManage: added support for image conversion (VDI/VMDK/VHD/RAW)
Solaris hosts: added IPv6 support between host and guest when using host interface networking
Mac OS X hosts: added ACPI host power status reporting
API: redesigned storage model with better generalization
API: allow attaching a hard disk to more than one VM at a time
API: added methods to return network configuration information of the host system
Shared Folders: performance and stability fixes for Windows guests (Microsoft Office Applications)