Share

Microsoft was once an avowed opponent of network computing, thin clients or anything else that threatened to harm Windows’ hegemony by putting the PC on a crash diet.

Over the years, Microsoft has outlasted a number of vaunted opponents in that debate; for instance, the Java-based New internet Computer flopped earlier this decade.

Microsoft no longer feeling threatened, has shown its willingness to cautiously embrace thin-client computing -- provided it is on its own, Windows-centric terms. This has been shown by its increasingly popular Terminal Services software, which lets users access applications running on corporate servers, and even the rollout of consumer web iniatives such as Windows Live and Office Live.

Microsoft has brought its affair with thin clients into the open, announcing two major licensing changes. One officially gives companies the free right to stream Windows Vista from servers down to users running thin-client hardware -- PCs lacking hard drives, though Microsoft refers to them with the semi-castrating term, "diskless PCs."

The second change is a new subscription licence called Windows Vista Enterprise Centralised Desktops (VECD), which allows companies to host Windows Vista or applications in virtual machines on centrally-managed servers that can be streamed out to end users’ PCs.

VECD requires an annual, per-device fee that Microsoft says varies on whether companies are using PCs or thin clients, but which the company otherwise declined to disclose.

Luring users into Software Assurance?

Though companies such as Ardence have also been offering streaming Windows for several years, "there was no licensing explicitly created by Microsoft to enable those scenarios," according to Scott Woodgate, director in the Windows Business Group. To be legal, Woodgate said, companies would have needed to buy full retail licences of Windows for "every virtual machine or disk image" hosted on their servers.

The new licences are meant to make deploying streaming and virtualised infrastructures easier and give "early adopters that want more flexibility to try out new architectures", said Woodgate. The licences are available only to large corporations paying for Software Assurance (SA) contracts with Microsoft.

Companies paying for the SA maintenance contract typically pay an additional 87% of the cost of their software licences divided over three years. In return, they are eligible for a number of benefits, though the chief one in most customers' eyes remains the right to the next major software release. That lost some of its allure in the last several years, as Microsoft failed to release several key product upgrades within three years. Small to midsize businesses can continue to purchase the retail licences, Woodgate said.

Brian Madden, the technical analyst and president of the Brian Madden Company, said that Microsoft’s new licences are an improvement in some respects. "This was a modernisation of the licence agreements so that what used to be a ‘don’t ask, don’t tell’ situation is now officially allowed," he said. But as with Microsoft’s release last summer of Windows Fundamentals, which let SA subscribers convert aging PCs into thin clients that get older operating systems streamed to them from a central server, Madden sees an ulterior motive.

"The reason they offer Windows Fundamentals is not because Microsoft wants to be your friend; it’s because they want to get you to upgrade [to Vista] and sign up for SA," he said.

Almost a wash?

Server virtualisation of streamed applications, as provided through products such as Microsoft’s Virtual Server 2005 and SoftGrid or VMware’s offerings, can ease the deployment of software applications by encapsulating them inside virtual machines, thus avoiding potential crashes resulting from incompatible applications.

Virtualised streaming software, which tends to rely on the local PC to cache and process parts of an application, also typically performs faster than Terminal Services, especially if it is a graphics-heavy application, Woodgate said.

By contrast, Terminal Services host and run all applications. They essentially treat PCs, whether fat or thin, as "dumb" clients, making them more vulnerable to network outages.

"From a licensing perspective, this is great that they are doing this, but I think it is a gamble for most companies to invest future dollars into a technology that is still evolving," said Brad Carpenter, senior information systems analyst at the local authority at Lane County, in the US state of Oregon. Lane County is moving 1,500 users to diskless PCs that will get all of their applications and Windows XP streamed to them from virtual machines hosted on central servers.

Carpenter is negotiating an SA agreement for Lane County with Microsoft for the first time. He plans to use three outside vendors to provide the virtualisation and streaming capabilities. Carpenter said that while Lane County expects to save money, unanticipated technical issues related to Windows Server make it "almost a wash."

"Time saved by virtualisation is a good thing but only if it not offset by time spent grooming profiles and managing printer definitions," he said.

Woodgate admits as much. For one thing, for each client PC, even if it only caches Vista temporarily in its memory and never installs it, companies must buy a full Windows licence and covering SA agreement, he said. That is true even if the maximum number of concurrent server users is much lower than the total number of devices. In other words, if a company has 1,000 PCs but only 500 employees are logging into the server at any given time, it would still have to buy 1,000 licences, not 500.

Woodgate also noted that Terminal Services remains more thoroughly tested, cheaper, and easier to deploy than server-based streaming, especially for small and midsize businesses.

For now, he said, diskless PCs and server virtualisation remain "niche" applications that will appeal mostly to well-heeled banks and government customers with very fast networks.