VirtualBox was chosen since it is an open source, free choice which is available on Windows, Mac, Linux, and Solaris. It is simply the easiest way for developer

VirtualBox was chosen since it is an open source, free choice which is available on Windows, Mac, Linux, and Solaris. It is simply the easiest way for developers to get started with a virtualized development environment. Neither John nor I are familiar with any other virtualization platform, but making Vagrant modular enough such that this is possible is definitely a good idea for the future. Thanks!