Oracle VirtualBox is the open source virtualization platform for enterprise as well as home use, it provides the software virtualization to x86 hardwares ie general purpose desktops. It released under GNU GPL License. You can download it from official website. With this you can run multiple guest operaing system on the VirtualBox host.
It supports multiple guest operating system:
- Windows NT
- Windows 2000
- Windows XP (32 bit/64 bit)
- Windows Vista (32 bit/64 bit)
- Windows 7 (32 bit/64 bit)
- Windows 2003 Server (32 bit/64 bit)
- Windows 2008 Server (32 bit/64 bit)
- Ubuntu 5.10 / 6.06 Desktop / 7.04 – 11.04
- Mac OS X
The Guest Additions is the add-on feature of VirtualBox, it increases perfomence of the guest operating system in several ways. Here i am listing some of the special feature of VirtualBox Guest Addition.
Mouse pointer integration:
This provides you with seamless mouse support. You will only have one mouse pointer and pressing the Host key is no longer required to “free” the mouse from being captured by the guest OS. To make this work, a special mouse driver is installed in the guest that communicates with the “real” mouse driver on your host and moves the guest mouse pointer accordingly.
- Shared folders:
- These provide an easy way to exchange files between the host and the guest. Much like ordinary Windows network shares, you can tell VirtualBox to treat a certain host directory as a shared folder, and VirtualBox will make it available to the guest operating system as a network share, irrespective of whether guest actually has a network.
- Better video support:
- While the virtual graphics card which VirtualBox emulates for any guest operating system provides all the basic features, the custom video drivers that are installed with the Guest Additions provide you with extra high and non-standard video modes as well as accelerated video performance.In addition, with Windows, Linux and Solaris guests, you can re-size the virtual machine’s window if the Guest Additions are installed. The video resolution in the guest will be automatically adjusted (as if you had manually entered an arbitrary resolution in the guest’s display settings).Finally, if the Guest Additions are installed, 3D graphics and 2D video for guest applications can be accelerated.
- Seamless windows:
- With this feature, the individual windows that are displayed on the desktop of the virtual machine can be mapped on the host’s desktop, as if the underlying application was actually running on the host.
- Generic host/guest communication channels:
- The Guest Additions enable you to control and monitor guest execution in ways other than those mentioned above. The so-called “guest properties” provide a generic string-based mechanism to exchange data bits between a guest and a host, some of which have special meanings for controlling and monitoring the guest.Additionally, applications can be started in a guest from the host.
- Time synchronization:
- With the Guest Additions installed, VirtualBox can ensure that the guest’s system time is better synchronized with that of the host.For various reasons, the time in the guest might run at a slightly different rate than the time on the host. The host could be receiving updates via NTP and its own time might not run linearly. A VM could also be paused, which stops the flow of time in the guest for a shorter or longer period of time. When the wall clock time between the guest and host only differs slightly, the time synchronization service attempts to gradually and smoothly adjust the guest time in small increments to either “catch up” or “lose” time. When the difference is too great (e.g., a VM paused for hours or restored from saved state), the guest time is changed immediately, without a gradual adjustment.The Guest Additions will re-synchronize the time regularly.
- Shared clipboard:
- With the Guest Additions installed, the clipboard of the guest operating system can optionally be shared with your host operating system.
Each version of VirtualBox, even minor releases, ship with their own version of the Guest Additions. While the interfaces through which the VirtualBox core communicates with the Guest Additions are kept stable so that Guest Additions already installed in a VM should continue to work when VirtualBox is upgraded on the host, for best results, it is recommended to keep the Guest Additions at the same version.
Starting with VirtualBox 3.1, the Windows and Linux Guest Additions therefore check automatically whether they have to be updated. If the host is running a newer VirtualBox version than the Guest Additions, a notification with further instructions is displayed in the guest.