VirtualBox is a type-2 hypervisor based virtualization software for x86-based hardware. It allows users to create guest virtual machines of different operating systems on top of the host operating system. VirtualBox can virtualize guest hardware, as well as a variety of peripheral devices such as disks, graphics card, sound card, network interface cards, and USB controller. VirtualBox supports various performance-enhancing features such as 3D graphics acceleration, USB 3.0 controller, CPU/disk hotplugging, nested virtualization (with Intel VT-x and AMD-V), and CD/DVD/disk pass-through. It comes with other useful features of virtual machine manager, such as virtual machine snapshot and cloning, command-line interface, network I/O rate limiting, host/guest shared folders, integrated RDP server for guest remote desktop, live migration and more. The VirtualBox package consists of an open-source (GPL) base package and proprietary extension packs for more features (e.g., USB 3.0, webcam passthrough, PCI passthrough. PXE boot, AES-based disk encryption).