When Dataprise, an IT services company, helped a customer with a desktop virtualisation project last year, it found itself dealing with desktop virtualisation's dirty little secret: No one - including vendors - seems to know how to licence the software.

When Dataprise, an IT services company, helped a customer with a desktop virtualisation project last year, it found itself dealing with desktop virtualisation's dirty little secret: No one - including vendors - seems to know how to licence the software.

Having run a successful pilot, Dataprise's client wanted to take the next step and deploy 700 virtual desktops, says Chris Sousa, director of infrastructure service at Dataprise. That's when the trouble began. Like many businesses, the customer - a manufacturer of fibre-optic cable - had an enterprise agreement with Microsoft, but its IT staff wasn't sure exactly what was covered in a virtualised environment. Apparently, neither was Microsoft, says Sousa, who noted that he called the company repeatedly seeking information.

"We'd get a different answer from a different person on a different day," he says. Sousa's experience is not unusual. In a study conducted by Info-Tech Research Group last year, Microsoft Windows licensing was the most-cited pain point for people implementing desktop virtualisation, according to John Sloan, lead research analyst at Info-Tech Research Group.

Microsoft responds that it has tried to improve its virtualisation pricing policies. Most recently, the software giant relaxed its licensing rules for virtual desktops and expanded rights to access a given virtual desktop from more than one computer.

The changes are "a step in the right direction," says Sloan, but he feels that Microsoft "hasn't gone as far as many would like." For example, although the new roaming rights allow users to log into their virtual desktops from devices outside of the corporate firewall, such as home PCs or airport kiosks, the virtual desktop is still licensed to a specific corporate PC. That means that a user may not be able to access his virtual desktop from another corporate PC, like one in a branch office, Sloan explains.

Confused yet? You're not alone. Even with all the changes, Microsoft licensing "is still so complicated that users and even resellers don't understand it," says Barb Goldworm, president and chief analyst of consultancy Focus LLC.

Not only are the specific vendor rules confusing, but IT managers also mix up the licensing of the virtualisation software (which serves as a connection broker and a virtual desktop running on a back-end hypervisor) and the licensing of the software that actually runs on the desktop (the operating system and applications).

Broader than any one vendor

But the problem is bigger than just Microsoft. All software vendors are struggling with this issue to some extent. When Citrix introduced XenDesktop 4 last fall, it changed from its traditional model - concurrent licensing - to one licence per named user. But customers quickly complained that they needed more flexibility. In some industries, for example, multiple users share the same device.

So Citrix quickly added per-device licensing and brought back concurrent licensing for its Virtual Desktop Infrastructure edition, says Calvin Hsu, director of product marketing at Citrix.

In some cases, IT managers throw up their hands and look for other options. When Michael Goodman, vice president and director of information systems and technology at Crescent State Bank in Cary, N.C., discovered that he'd have to buy two licences for the same Windows operating system - one for a thin client and one for the operating system running on the server - "it really knocked down my payback period on the ROI". That was one of the reasons he skipped thin clients and went with a Pano Logic device, which serves as a dumb terminal connected to the operating system, which is running on a server in the data centre.

In other cases, IT managers simply wing it, making a good-faith effort to pay the proper licensing fees without knowing exactly what licensing fees are required, which is what Sousa's client did. "We were trying to be upstanding citizens and not rip anybody off, but we couldn't get definitive answers," he says.

Complex, like the tax code

Big picture: Software licensing for virtual desktops is incredibly complex, confusing and, in some cases, prohibitively expensive. "It's like the IRS tax code," says Dave Buchholz, principal engineer at Intel's IT unit, who has been running a research project that looks into all aspects of desktop and application virtualisation.

The problem is multifaceted. Like an onion, if you peel away one layer another layer appears. At its most basic, the problem reflects a fundamental shift in the industry: Software is being divorced from hardware at a faster rate than ever before, mostly because of virtualisation.

As software vendors deal with this shift, they are experimenting with different approaches. Some still tie the software licence to a specific piece of hardware, some are moving to a user-based licence, others sell concurrent-user licences and still others do a mix of all three.

On top of that, there are different flavours of virtualisation at the desktop level, such as virtual desktop infrastructure (VDI), application virtualisation and operating system streaming. And different types of licensing plans can apply to the different flavours. Moreover, there are many different layers of software in any virtualised environment - the operating system, the virtualisation software itself, the applications - each of which has its own licensing requirements.

The confusion over licensing of Microsoft products is tripping up small and mid-size companies in particular, because they may not have Software Assurance plans, says Sloan. Large enterprises that are covered through SA and enterprise agreements sometimes don't feel they need to keep track of all of the details, even though they should.

How large shops are coping

Bill Galinsky, senior vice president of global IT infrastructure at software vendor CA Technologies, started an internal desktop virtualisation pilot project in January 2010. So far, he has virtualised 500 desktops, and he expects to reach 2,000 of the company's 13,000 employees within a year.

When Galinsky started the pilot, he bought Microsoft VECD licences for the virtual desktops. "That was something we nailed early on with Microsoft - it wasn't a challenge, it was just [a matter of] understanding what that cost was," he says. Although he knew that Microsoft has since changed some licence policies, Galinsky said he wasn't specifically aware that as of 1 July the VECD was going away and those rights would now be included in the SA. "If [the VECD] went away," he says, "I'll be asking Microsoft for a refund or a credit."

In any event, those changes are probably covered under CA's SA and enterprise agreements, which for all practical purposes base the licensing on the number of users rather than pieces of hardware, he says. "In our case, our enterprise agreement works out to a ratio of around 1 to 1.27. So every employee can run 1.27 copies of the operating system and Microsoft Office."

Vince Kellen, CIO at the University of Kentucky, is also facing the pricing conundrum as he considers how to virtualise about 1,000 desktops on campus. "It's a challenge to get the software licensing that you want," he says.

But, in his case, Microsoft and other big software vendors aren't the problem. Kellen says he's covered under enterprise-wide contracts geared for academic institutions, "but as soon as we get into other software outside of our normal contracts, it can get more difficult."

Some of the university's smaller vendors, especially those selling niche academic and clinical applications and specialised math or statistical software packages, are "a little harder to work though the contracting," Kellen says.

Over time, he hopes that software vendors can find a less expensive pricing model that is desktop-virtualisation-friendly - one that licenses concurrent users instead of specific named users, for instance. "This will be hard for smaller vendors, I think, as larger vendors have a broader portfolio of software products and perhaps business models which will give them flexibility," Kellen adds.

The whole concept of software licensing is morphing as virtualisation grows and consumer electronics invades corporate IT. "As corporate employees start using many different devices - smartphones, laptops, iPads - corporations are asking 'How many licences am I going to have to buy?'" says Buchholz.