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。

This is a major update. The following major new features were added:

• VMM: new APIC and I/O APIC implementations that result in significantly improved performance in certain situations (for example with networking, bug #15295)
• VMM: added support for Hyper-V paravirtualized debugging of Windows guests
• VMM: emulate even more MMIO and shadow pagetable exits without going back to user mode
• GUI: overall migration to Qt5 (bug #11775)
• GUI: passive API event listener improving the VM GUI performance and response time
• Audio: added HDA (High Definition Audio) support for newer Linux guests
• Audio: added on-demand timers which should improve the overall performance and reduce the CPU consumption
• Audio: more fine-grained volume control for the AC'97 emulation, which now also takes the master volume control into account
• better support for Python 3

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

• VMM: activate the x2APIC by default for Linux guests
• VMM: many more fixes
• GUI: the Detach UI action is now a part of the VM Machine menu
• GUI: reworked session information window
• GUI: the new VM wizard now allows to choose the VM location for the VM which is being created
• GUI: fixed location of touch events in unscaled HiDPI mode (bugs #14366, #14367)
• GUI: various bugfixes and internal cleanup
• Storage: use fallocate() or similar if present to speed up creating fixed-sized disk images (bug #5967)
• Storage: implemented NVMHCI-compatible storage controller
• Audio: various bugfixes and infrastructure improvements
• E1000: implemented interrupt throttling for performance improvements
• EFI: many improvements, for example allow to boot from USB
• OVF: improved handling of signed manifests
• API: Windows XP guests and Windows 2003 server guests now default to the E1000 T Server network card
• VBoxSVC: fixed several memory leaks when handling .dmg images
• Installers: ship VBoxBugReport
• Windows hosts: reworked COM proxy (e.g. bug #8298)
• Linux installers: no longer rely on DKMS for module rebuilding
• Linux Additions: fix a problem when updating the initramfs after the guest modules are compiled (bug #15579)
• Linux Additions: try to fix a problem where the OpenGL libraries where loaded by the X server when we only support X clients (bug #15574)