VirtualBox虚拟机三大特点：免费、小巧、多国语言（含中文）。VirtualBox可以跨平台运行操作，支持安装Windows (NT 4.0、2000、XP、Server 2003、Vista、Win7、Win8、Win8.1等)、DOS/Windows 3.x、Linux、OpenBSD等系列的客户操作系统。

距离上次4.2.18更新刚好一个月，VirtualBox又发布最新的稳定版VirtualBox 4.3.0，不过依旧是集中修复大量bug，其中典型的就是4.2.16和4.2.18两个版本的网卡桥接驱动在Win8.1下引起了异常的睡眠和休眠故障，这次新版已解决该问题，其他就是惯例的软件性能和稳定性提升。

VirtualBox 4.3.0更新日记：

新增内容：

VMM: major rewrite of the VT-x code and the AMD-V code including many bug fixes and performance improvements (for example bug #9659)

VMM: introduced a lightweight instruction interpreter for situations not handled by hardware virtualization

GUI: extended messaging mechanism (new non-modal popup overlays used to show non-critical warnings and provide user with additional information)

GUI: keyboard shortcuts management (input page of global preferences extended with possibility to edit general keyboard shortcuts for VirtualBox Manager and Virtual Machine)

GUI: video capturing support (bug #4766)

Added USB touch device emulation

Added experimental support for webcam passthrough complementing USB passthrough (see the manual for more information)

Added SCSI CD-ROM emulation, including boot support

VRDP: support for IPv6

Guest Control: guest sessions now are running in dedicated, impersonated session processes (needs at least Guest Additions 4.3 installed)

Guest Control: implemented IGuestFile support

NAT: experimental virtual router mode: several VMs are attached to the same internal network and share one NAT service (see the manual for more information)

修复或者更改：

VMM: significantly improved performance of NetWare 5.x/6.x guests on host systems without nested paging support

VMM: fixed losing host NMIs while in VT-x guest-context

VMM: changed order of actions in emulated task switch (bug #10532)

VMM: allow to activate VT-x while in SMX mode and provide more information if that is not possible

GUI: update check uses https

GUI: numerous minor internal cleanups and bug fixes

GUI: HID LEDs synchronization when switching between guest window(s) and host (Mac OS X hosts only)

GUI, VBoxManage: when unregistering a VM, also unregister the hard disk images which are used exclusively (bug #10311)

GUI: use the number of physical presented processor cores instead of the number of logical processor cores to check if the users assigned too many virtual CPUs to the guest

Snapshots: made live snapshots work again (bug #9255)

Teleportation: made it work again (bug #9455)

Storage: implemented AHA-154x compatibility mode in the emulated BusLogic SCSI HBA

Storage: significantly improved performance of large ATAPI PIO transfers (BeOS, Minix 3 guests affected)

Storage: added floppy formatting emulation (NB: cannot be used to change existing media geometry)

Settings: global and per-VM default frontend configuration, useful to select the use of alternative VM frontends

Settings: limit depth of snapshot tree to 250 levels, as more will lead to decreased performance and may trigger crashes

Settings: the per-VM hwvirtextexcl setting has been replaced by a global hwvirtexclusive property

Main: new event queue implementation which does not use the host's native event queue for processi