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: more work on improving the emulation of certain MSR registers
• VMM: fixed a VERR_INVALID_RPL Guru Meditation when booting certain guests
• VMM: experimental support for SSE 4.1 / SSE 4.2 passthrough, see the manual for more information how to enable it
• VMM: fix for recent Linux kernels with software virtualization
• GUI: experimental HID LEDs synchronization for Windows hosts, see the manual for more information
• GUI: warn the user if the Oracle Extension Pack is not installed and the user tries to activate the remote display feature
• GUI: make sure that a minimized guest (using mini toolbar in fullscreen/seamless mode) keeps the minimized state
• GUI: popup banner's "do not show this message again" check-box replaced with corresponding button
• GUI: network adapter cables can now be connected/disconnected directly through the running virtual machine Devices / Network menu a Network status-bar indicator
• GUI: the new VM wizard now proposes 64-bit guests on 64-bit hosts by default; better distinction between 32-bit OS types 64-bit OS types
• GUI: better error message if appliance import fails
• GUI: allow to set host-combination to 'None' using the Global settings / Input page
• GUI: don't switch the guest to a black screen during online snapshot merge
• VBoxManage: when exporting an appliance, support the suppression of MAC addresses, which means they will be always recreated on import, avoiding duplicate MAC addresses for VMs which are imported several times
• AHCI: fixed a VM hang during suspend under certain circumstances
• AHCI: fixed a VM hang during online snapshot merge under certain circumstances
• AHCI: fixed a bug which resulted in Windows XP guest hangs if a SATA CDROM is attached
• AHCI: fixed a Guru Meditation under certain conditions
• AHCI: ejecting a CD/DVD medium failed under certain conditions
• AHCI: disk hotplugging fixes
• NAT: transparent handling of host sleep/resume and network configuration changes if the dnsproxy is enabled or if the hostresolver is used
• NAT: fixed crash and misbehaviour under some circumstances with ICMP packets having TTL=1
• NAT Network: fixed IPv6 reassembly
• NAT Network: ping proxy implemented
• OVF: fixed reading of the OVF 0.9 section element
• OVF: several fixes
• 3D: several fixes, multiscreen fixes
• 3D: include 3D content in captured videos
• 3D: include 3D content in captured screenshot
• VGA: proper handling of legacy graphics modes if the Guest Additions are active
• USB: fixed crash during isochronous transfer under rare circumstances
• BIOS: better disk geometry handling of SCSI drives
• API: fix crashes in Java API clients using the XPCOM binding, happened with output parameters only
• VBoxSVC: documented the handling of host power management events (see the manual for more information) and added an extradata item for configuring the handling of the battery-low event
• VBoxSVC: fixed a bug which could trigger a crash if a VM snapshot was restored the second time and the VM has associated bandwidth groups
• VBoxSVC: properly detect ifconfig if located in /bin
• Shared Folders: fixed a failure to restore transient shared folders when starting a VM from a saved state
• Mac OS X hosts: fixed issue when the application icon was frozen in the dock if the bridging interface was not connected to a network
• Linux hosts: also consider the physical package ID when determining the number of physical CPU cores
• Linux hosts / guests: don't warn in kernel log if memory allocation fails
• Solaris hosts: fixed the autostart SMF script
• Windows hosts: fixes for non-ANSI code page user names and similar environment contents
• Windows hosts / guests: fixed setting and using a guest user's process environment variables (relevant for Guest Control)
• Windows Additions: fixed handle leaks in VBoxTray
• Windows Additions: fixed a crash while detecting active guest users
• Windows Additions: fixed restoring backed up D3D files on XPDM -> WDDM upgrade
• Guest Control: fixed setting and using a guest user's process environment variables
• Linux Additions: support Enterprise Linux 6.5 kernels
• Linux Additions: fixed CPU hot-remove on newer Linux kernels
• Linux / Solaris Additions: don't automount a shared folder which is already mounted
• X11 Additions: support X.Org Server 1.15