It's been almost a year since Microsoft officially announced their licensing policies for using Vista in virtual machine environments. Today they made a few changes to those policies.
There are actually two sets of rules concerning Vista and VMs, depending on your use case. The first governs which version of Windows Vista you're allowed to run in a VM running locally on your computer. The second rule dictates when you're allowed to access Vista remotely across a network.
Running Vista in a local virtual machine
Under the old rules, you must have been using Windows Vista Business edition or higher to be allowed to run in a VM. In other words, if you had a Mac, and you bought VMware Fusion to run Vista in a local VM, you had to buy at least Vista Business edition. If you just bought the Home edition of Vista, you were breaking the law!
Of course this was crazy and no one followed it, so today Microsoft officially announced that ALL editions of Vista, including the "cheap" home editions, can legally be used in a virtual machine.
Connecting to Vista remotely over a network
The second aspect of yesterday's announcement is about pricing, specifically, the cost of something Microsoft calls "Vista Enterprise Centralized Desktop," or VECD.
VDI environments (where instances of Windows XP or Vista run in the data center in VMs or on hardware blades) have been gaining popularity for several years. The only problem was that Microsoft didn't really come out and say whether it was actually legal to do this. Was it legal for a coming to buy a copy of Vista, run it in the data center, and then provide access to it via full desktop server-based computing?
In April 2007, Microsoft said "yes," you can do this if you pay them some extra money on top of the money you already paid to buy Vista. This "extra money" you have to pay is to buy an additional license called "Vista Enterprise Centralized Desktop" (VECD). The catch is that you can only buy this VECD license if you have the enterprise edition of Vista and if that copy of Vista is currently enrolled in Microsoft's subscription program, Software Assurance. The April 2007 price for the VECD license was $78 if you're connecting from a rich client device, and $196 if you're connection from a thin client device.
Yesterday's announcement from Microsoft did not change the terms of the VECD license, but it did lower the price. The additional VECD license is now $23 when connecting from rich clients, and $110 when connecting from a thin client device.
What does this mean?
The Vista licensing rules as they were laid out last April were almost universally received with confusion, contempt, and people generally claiming "WTF?" The feeling was that Microsoft didn't "get" virtualization, and the April 2007 rules were Microsoft's arrogant way of saying, "F you. If you want to do virtualization, you will do it on our terms. If you don't like it, then run Vista locally as it was designed for!"
Now Microsoft has caved to industry pressure. They've realized that people are going to virtualize and remotely deliver Vista whether Microsoft likes it or not, so they might as well try to offer a licensing program that people can be in compliance with.
The only thing that I still don't understand is why Microsoft forces customers to have Software Assurance in order to use VECD. This just seems like another way to force people onto SA. But then again, they're Microsoft. What can you do? Not use Windows?