its interface is available as a WSDL file. This file is generated based off a XIDL(Extended Interface Definition Language) file which is also used to define the interface for all the APIs VirtualBox provides (web service bindings for Java, Perl, PHP and Python as well as static library bind-ings for C, Microsoft COM and XPCOM interfaces) in all the different languages. The fact alone that the SOAP interface is treated as any other (non-web) API raises a warning that VirtualBox developer stake no special precautions when pushing changes to the web API.