K-12 schools can use Microsoft School Agreement. This is what Fairfax County Public Schools uses. FCPS spent $2.9 million on Microsoft School Agreement in FY2009 for its roughly 98000 desktops and laptops. That comes out to about $30 for each PC, which, considering the retail cost of Windows Professional and Office Professional, is a really good deal. However, from the School Agreement information booklet:
School Agreement requires an institution-wide commitment for any application, system, and Client Access License (CAL) products selected. To that end, you must include all of the eligible PCs in the participating school(s) or district. Eligible PCs include all of the Pentium III, iMac G3, or equivalent or better machines*. You must also include any additional machines within your institution on which any of the software will be run.
*Includes machines with similar processors, such as Intel Celeron and AMD Athlon.
In other words, if a school has PCs that are Pentium III or iMac G3 or better, they have to count them even if those PCs won't be using some or even any of the products covered under the agreement. Another way to put it is if a school runs Windows on only half of its computers (the other half could be Mac or Linux, etc.), and all of those computers are less than 5 years old, the school wouldn't pay Microsoft any less than if it ran Windows on all its computers. Older computers only have to be counted if they are going to run software from the agreement, otherwise they can be left out.
Higher education can utilize a similar program, the Microsoft Campus Agreement. The lock-in here is potentially worse:
Campus Agreement pricing for any application, system, and CAL products you select is based on a count of your total faculty/staff FTE employees and requires organization- or department-wide coverage. To that end, you must include all FTE employees in the participating institution(s) or departments(s) (including student employees) using the calculation below.
Non-knowledge workers, such as maintenance, grounds keeping, and cafeteria staff may be excluded from the faculty/staff FTE employee count if they do not use institutional computers.
So colleges and universities don't even pay based on how many computers there are, but based on how many people they hire. Part-time faculty and staff are included as fractions.
From a financial perspective, then, it makes the most sense to run Windows on every computer.
So what about thin clients?
I found an interesting article from Computerworld, written about three years ago. The Software Assurance mentioned is included with both School and Campus Agreement options. Microsoft has a Vista Enterprise Centralized Desktop program for thin clients, it seems. However, it's unclear exactly what the interaction between that and a School or Campus Agreement would be. In any event, from the information document:
Thin client license. For thin clients, a single annual subscription purchase is required. With this subscription, companies can install unlimited copies of Windows Vista Enterprise or earlier operating systems, such as Windows XP Professional or Microsoft Windows 2000 Professional, on any number of physical servers, as long as the VMs are accessed only by licensed client devices. Users can access up to four running VM instances on up to four servers per subscription license. In addition, the annual subscription has Software Assurance built-in and provides for earlier versions, and well as upgrades that are made available within the license time frame.
To use desktop applications (for example, Microsoft Office Professional 2007) from the licensed device, each accessing device must be licensed for the application. Windows Vista Enterprise Centralized Desktop does not include application licenses.
It sounds like the OS would be licensed on a concurrent user basis (assuming the thin client disconnects from a VM when it isn't in use), while Office would need to be licensed per-thin client that might potentially use the application. It's also unclear if licensing under VECD would be more or less expensive than licensing under SA/CA. At the least, though, VECD seems to be less restrictive than the traditional licensing agreements, but perhaps only by necessity. However, it's also possible that Microsoft assumes the use of a Microsoft-based thin client, and they would demand a more stringent contract in the presence of, say, a Sun thin client that runs no Microsoft OS on-board.
So yes, maybe a school district or university stands to save by using alternative platforms such as Linux or Solaris, or would like to do graphics work on Macs. But unless they completely dump Microsoft, or opt for a different and probably more expensive (unit cost-wise) licensing agreement, this is at best difficult to do, especially in economically hard times. That said, I'm not saying institutions shouldn't try, and VECD may be a good way to go in and of itself if I've understood it correctly.
UPDATE 1/24/2010: I want to clarify the volume licensing mentioned above is on a subscription and not a perpetual basis. Customers have to recount and repay for each and every eligible system on a regular basis (either annual or three year contract).