On Monday, Microsoft announced a change in licensing that means they will officially support Vista when used in VDI and OS streaming (i.e. "diskless PC") scenarios. There are two parts of this announcement:
- A modification to the Vista Enterprise license agreement that allows customers to use Vista Enterprise on a diskless PC.
- A new product (well, a new license anyway) called "Vista Enterprise Centralized Desktop," which allows customers to access Vista enterprise sessions remotely running on server hardware.
As always, there's a catch. And it's a big one! In this case, both of these changes are only available to Software Assurance customers!
Let's dig into what this announcement means.
First of all, the modification to the Vista Enterprise license agreement that explicitly allows you to use Vista Enterprise on a diskless PC is geared towards OS streaming scenarios like Ardence. But why did Microsoft have to make a change to the license agreement? Haven't people been using Ardence for years?
Of course they have. The key is how the Microsoft licenses have been (and continue to be) worded. Microsoft desktop OS licenses (like Windows XP and Vista) are licensed per named device, not per user. The "named" part of "per named device" means that if one user accesses the OS from multiple devices, two device OS licenses are needed--one for each device--even if the user never uses both at the same time. When you get into the world of streaming OSes, it can be confusing as to what counts as a "device." Of course everyone knows that if you're streaming a single shared disk image to 100 users, you still have to buy 100 licenses (even though it's just one single installed instance of Windows). That's not the problem.
The problem is that you have to buy a full OS license for every device a user connects from. So a scenario where each user is streaming their own image to multiple computers (not at the same time), you would still need to buy separate licenses for each computer.
Of course in reality, no one did this. People felt that as long as they had an XP Pro license for each user, they were covered. And since Microsoft didn't explicitly specify what was and wasn't allowed for this use case, it didn't really matter.
That all changed on Monday. Now Microsoft has explicitly granted the license right to stream Vista if you're using Vista Enterprise and if you're a Software Assurance customer. If you're not a Software Assurance customer? To bad--you can do it the old way.
The second part of this announcement is the new license called "Vista Enterprise Centralized Desktop" (VECD). This allows Vista Enterprise to be run in VMs on server hardware and then accessed via regular PCs or thin clients. Of course everyone reading this knows that this is called "VDI," but for some reason, Microsoft never mentions the term "VDI" in any of their announcements or new licensing documentation.
Here's what's weird about VECD: This is something you have to pay for! The price varies, depending on whether you will access the Vista VM from a thin client or from a regular PC. And of course since this is for SA customers only, Microsoft won't publicly disclose the prices.
For VECD, I'm not clear on whether it will be required in addition to your existing Vista Enterprise license, or whether it will replace your Vista Enterprise license. It would seem strange if it was an additional license, because since this VECD product is only available via SA, Microsoft has said that non-SA customers can continue to buy full Vista Enterprise licenses if they want to use VDI. This would suggest to me that the VECD license must be cheaper than a full Vista Enterprise license, and it would therefore be used by SA customers instead of a full Vista Enterprise license.
If you think about it, this is exactly what Microsoft did with the TS CALs. Back in the NT4 days, you had to buy a full Windows NT Workstation license to use Terminal Services. And then with Windows 2000, Microsoft created the TS CAL which was only about 40% of the price of a Windows 2000 Professional license. (One could even speculate that had SA existed in 2000, the TS CAL would've been SA-only too!)
Does anyone know anything more about this? Feel free to post what you know to the comments below.