Installing and running a mail server becomes as easy as importing such an appliance into VirtualBox. With VirtualBox, such a complex setup (then often called an “appliance”) can be packed into a virtual machine. For example, installing a complete mail server solution on a real machine can be a tedious task. Software vendors can use virtual machines to ship entire software configurations. Since you can configure what kinds of “virtual” hardware should be presented to each such operating system, you can install an old operating system such as DOS or OS/2 even if your real computer’s hardware is no longer supported by that operating system. This way, you can run software written for one operating system on another (for example, Windows software on Linux or a Mac) without having to reboot to use it. VirtualBox allows you to run more than one operating system at a time. Running multiple operating systems simultaneously.The following screenshot shows you how VirtualBox, installed on a Mac computer, is running Windows 7 in a virtual machine window: It can run everywhere from small embedded systems or desktop class machines all the way up to datacenter deployments and even Cloud environments. VirtualBox is deceptively simple yet also very powerful.

You can install and run as many virtual machines as you like - the only practical limits are disk space and memory. So, for example, you can run Windows and Linux on your Mac, run Windows Server 2008 on your Linux server, run Linux on your Windows PC, and so on, all alongside your existing applications. Secondly, it extends the capabilities of your existing computer so that it can run multiple operating systems (inside multiple virtual machines) at the same time. What does that mean? For one thing, it installs on your existing Intel or AMD-based computers, whether they are running Windows, Mac, Linux or Solaris operating systems. VirtualBox is a cross-platform virtualization application.

Oracle virtualbox on windows 8.1