Virtual machines are a very neat idea which is spreading fast. The idea of a whole “machine” with operating system, files, data and pre-configured applications waiting ready to be started with a few clicks or keystrokes is pretty compelling. Managing virtual machines has been a largely manual process for most people so far, however. VMWare are pushing to become the de-facto virtual machine infrastructure vendor, and have recently decided that getting people to build software around their virtual machines will help build a solid customer base. One result of this is the recent release of a Java API for managing virtual infrastructures.