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: fix for a bug in the Local APIC emulation causing a BSOD when booting certain guests (4.3.0 regression; bug #12240)
• VMM: fixed loading of saved states if VT-x/AMD-V was disabled (4.3.2 regression; bug #12291)
• VMM: fixed single-stepping inside the guest for certain instructions (VT-x only; bug #10947)
• VMM: fixed a performance issue involving APIC accesses after rebooting a VM (4.3.0 regression; VT-x only; bug #12296)
• VMM: fixed TPR patching to be enabled for 32-bit guests even when the chosen guest type is 64-bit (4.3.0 regression; AMD-V only)
• VMM: fixed occasional VINF_EM_TRIPLE_FAULT errors on hosts without the unrestricted guest execution feature (bug #12198)
• GUI: don't bother the user with the BPP warning if no Guest Additions are installed
• GUI: fixed machine-window paint artifacts on VM reboot / guest-screen resize
• GUI: make sure the assigned license and description are attached to the exported appliance
• GUI: fixed bugs in close VM action restrictions handling (bug #12333)
• GUI: fixed incorrect wizards text colors for some unusual look and feel styles (bug #11743)
• GUI: should restore seamless mode as soon as possible after VM reboot or shutdown
• GUI: fixes for medium enumeration
• GUI: the OS X hot corners were not accessible while a VirtualBox VM is running (Mac OS X hosts only; bug #4139)
• GUI: fixed an old bug which bared the host from cleanly shutdown / reboot if the VM selector window is open (Mac OS X hosts only; bug #8254)
• Host-only Networking: fixed creating of host-only network interfaces (4.3.0 regression; bug #12182)
• NAT: don't run into an infinite loop in case the host cannot access any DNS server (4.3.0 regression; bug #12300)
• NAT: don't re-connect the cable if the DNS information changes and the cable was disconnected before (4.3.0 regression; bug #12225)
• NAT: fixed several issues with automatically starting / terminating of NAT networks on VM start / stop and configuration changes
• VBoxNetDHCP: don't block prevent VBoxSVC from terminating (bug #12264)
• 2D Video acceleration: fix crashes on presentation mode switches (bug #9194)
• BusLogic: allow to run VMs with more than one BusLogic SCSI controller enabled
• Keyboard: fixed a VM crash if a VM was resumed from a saved state where at least one key was pressed (bug #11289)
• VBoxSVC: fixed a heap corruption under certain conditions (4.3.0 regression)
• VBoxSVC: fixed a race leading to a hang during initialization (bug #12349)
• OVF: fixed import logic for OVF appliances containing multiple VMs
• OVF: improved logic for finding an appropriate image format during OVF import
• API: block the removal of the current snapshot if it has child snapshots (only relevant for VMs without snapshottable hard disks, their presence always prevented removal), which resulted in VM configuration corruption
• API: mark VM configurations with snapshots but without current snapshot as inaccessible, as this combination is nonsense
• API: fixed information for some automatically generated events (only with XPCOM, Windows host was not affected), which caused errors when getting some of the attributes over the webservice (bug #12379)
• SDK: extended the functionality coverage for the C bindings
• Guest Control: various bug fixes and improved VBoxManage help (bugs #8072, #11044, #12336, #12338, #12346, #12371)
• Windows hosts: another attempt to fix the massive DPC latency (bug #6242)
• Windows host installer: make registering file extensions optional, contributed by Tal Aloni (bug #8009)
• Mac OS X hosts: properly sign the kernel extensions for Mavericks hosts (bug #12256)
• Mac OS X hosts: fixed a bug where the VirtualBox dock icon was not properly removed from the dock after a VM terminated preventing Mavericks hosts from shutting down (bug #12241)
• Mac OS X hosts: fixed minor installer issue (bug #12275)
• Linux hosts / guests: Linux 3.13 compile fixes (bug #12358)
• Linux guests: build the vboxvideo kernel module correctly on OL/RHEL 6.1 guests (bug #11996)
• Linux guests: make 3D work on Slackware 14.1 (bug #12320 comments 3 and 4)
• Guest Additions/3D: fixed an occasional dead-lock (bug #12319)
• Windows Additions/3D: fixed possible memory leaking (bug #12228)
• Windows Additions/XPDM: use separate tables containing valid video modes for each virtual monitor
• Windows Additions: fixed automatic logins for Vista and newer Windows guests (bug #12332)