The licensing requirements for Windows Vista seem to me to be quite awkward for web and software developers on a budget - particularly for those who don't actually want to run the operating system as their development platform.

As with XP, the OEM license for Vista (which is the relatively affordable type you buy with a new PC, or from a PC wholesaler) will only allow one transfer of the license from one machine to another. Perhaps this isn't too bad if you use Vista as your main Operating System.

But the only Vista licenses which will entitle you to run Vista under virtualisation (running Windows as a "guest operating system" on Linux, for example), are the Business or Ultimate versions. What about multiple installations, or re-installation? Does the OEM license regard these as the same as a transfer? Under virtualisation, the guest operating may get installed afresh several times. It's also useful to be able to run several instances of the same operating system at once.