VirtualBox是一款免费且开源的虚拟化软件，允许用户在他们的计算机上创建和运行虚拟机。使用VirtualBox，用户可以在他们的计算机上同时安装和运行多个操作系统，而无需创建单独的分区或购买额外的硬件。

VirtualBox的主要优点之一是易于使用。即使是对虚拟化技术几乎没有经验的人，它也很容易安装和设置。VirtualBox还提供了广泛的自定义选项，包括调整分配给每个虚拟机的RAM、CPU核心和硬盘空间的能力。

VirtualBox的另一个重要特点是其与多种操作系统的兼容性。用户可以在他们的虚拟机上安装和运行Windows、Linux、macOS及许多其他操作系统。这使得它成为一个对开发人员、软件测试人员以及任何需要在单台计算机上运行多个操作系统的人来说非常优秀的工具。

VirtualBox 还提供了一系列高级功能，例如对 USB 设备、共享文件夹和网络适配器的支持。这些功能使得运行需要硬件或网络资源的软件成为可能，例如虚拟路由器、防火墙和服务器。

VirtualBox 是任何需要在一台计算机上运行多个操作系统的人的绝佳选择。其易用性、广泛的自定义选项以及与许多不同操作系统的兼容性，使其成为开发人员、IT 专业人员和家庭用户的多功能而强大的工具。

关键功能：

• 跨平台兼容性。
• 直观的图形用户界面。
• 支持各种操作系统。
• 与主机操作系统的无缝集成。
• 快照和克隆。
• 网络功能。
• 虚拟设备支持。
• 扩展包用于增加功能。

• 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)

In addition, the following items were fixed and/or added:

• 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 processing VirtualBox events anymore
• Main: eliminate the use of SysV semaphores on all host OSes other than Windows, namely Linux, Solaris and Mac OS X, with the consequence that no system reconfiguration is needed to run more than approximately 100 VMs
• Main: use the XDG standard configuration folder instead of .VirtualBox on systems where it is appropriate (bug #5099)
• Main: extension pack framework can now support loading HGCM modules, contributed by Jeff Westphal
• VBoxManage: list more information about hard disk/DVD/floppy media, and support the --long option to show really all available details
• VBoxManage: added support for optional command line parameters for the automatic Guest Additions update
• VBoxManage: added support for listing active guest sessions, guest processes and/or guest files via guestcontrol list
• VBoxManage: added support for closing active guest sessions via guestcontrol session close --session-id | --session-name | --all
• VBoxManage: added support for terminating active guest processes via guestcontrol process kill|close|terminate --session-id | --session-name ... or guestcontrol [p[s]]kill --session-id | --session-name ...
• VBoxManage: added support for watching guest sessions via guestcontrol watch
• VBoxManage: added modifyvm --triplefaultreset to make the VM reset on triple fault instead of triggering a Guru Meditation (see the manual for more information)
• 3D support: several fixes
• 3D support: several fixes for Mac OS X hosts
• OVF: several fixes
• Extpack Installer: make it work if the file is located in a folder with special characters
• Keyboard: fix for reporting key sequences like Ctrl+Alt+Del for the USB keyboard emulation
• Shared Clipboard/X11: support for BMP-format images, contributed by François Revol
• Mac OS X hosts: limited support for Mac OS X 10.9 (Mavericks)
• Mac OS X hosts: use a launchd script instead of the deprecated StartupItem mechanism (bug #8940)
• Windows hosts: don't cause massive DPC latency (only on certain hosts; still needs improving; bug #6242)
• Windows hosts: consider symlinks when retrieving volume information (bug #11962)
• Windows hosts: fixed an issue with USB2 devices being inaccessible when plugged into USB 3.0 ports
• Windows Additions: fixed misbehavior with guest display power management (WDDM driver only; bug #11170)
• Windows Additions: fixed memory leak caused by WTSQuerySessionInformation() on Windows 2000 guests (bug #12072)
• Windows Additions: ability to track guest user idle times through the newly introduced event IGuestUserStateChangedEvent
• Linux Additions: fixed udev detection in the init script with Linux 3.x kernels