When I was in my teens, my school Physics class was taken on trip to the Royal Institution, and the star speaker we saw was  Eric Laithwaite. He demonstrated a famous experiment of his (lifting a spinning gyroscope which was too heavy to lift when at rest). Wikipedia says he "had a habit of championing the ideas of amateurs over those of experts" and this came out right at the end when he made an aside about centrifugal force. "Do they teach you there is no such thing as centrifugal force ?"  "Yes" we murmured: we were taught that there is no force which pulls something at the centre of a circle to the outside, only centripetal force which pulls an object on the outside towards the centre, making it go round in a circle. Laithwaite went on "You know Newtons third law ? ... Action and reaction are equal and opposite ?" we  did. "So... How can there be a force acting only one way on the the string ?   If something is being pulled inwards, something else must feel a force going outwards. It just depends which end of the string you're standing at." And quite quickly one of the teachers reminded us the Laithwaite was so eminent that the examiners hadn't caught up with him.

Until today I hadn't heard the news that we had announced a change to Virtualization licensing of the home versions of Vista. I spent the day with some journalists going through different kinds of Virtualization (Hyper-V , Presentation Virtualization with Terminal Services and Application virtualization -neé Softgrid). Somewhere the subject of applications which don't run on Vista came up. I think this problem is overstated, as I said responding to a comment by "CW"  to an earlier post.  OS changes break stuff. The bigger the changes the bigger the risk of breakage and although we put huge effort into keeping it small, XP broke stuff, XP service pack 2 broke stuff, and Vista breaks stuff: but not that much. However if you work in an organization with a problem with compatibility, then Virtualization can be a "Get out of jail free card" . Not just hardware Virtualization with Virtual PC / Virtual Server / Hyper-V / Third party products (we had to show the journalists this post from May '07 to be clear that you can use third party products), but also hosting the problem application on terminal services, or streaming it with Softgrid App-Virtualization.

Now, Kelly Fiveash from the Register latched onto "Get Out of Jail Free" and used it a piece she posted later in the day. Actually she used it three times. But I didn't say it was a get out jail card for Microsoft or for Vista. I was about to set off on huge rant about being misquoted. Until Prof. Latithwaite's string came to mind. (I bet you were wondering how I was going to bring the first two paragraphs together).  It depends which end of the string you stand at. Perceived application incompatibility does worry customers, "you can always virtualize your way out" is a solution for us as much as for them.

The Licence currently on the web site hasn't been updated yet, so I can't tell if we only allow these versions to be run in a virtual machine, or whether we give a license to run a virtualized copy on top of a normal copy; the latter is the case in Vista-Enterprise - if it's only the former for the home versions we're only providing "get-out-of-jail cards." to enterprise customers.