There's a fight going on in the virtualisation market: Parallels versus VMware. Both companies have a new desktop virtualisation product due out very soon -- VMware Fusion and Parallels Desktop for Mac 3.0 -- both cost the same, and have similar features sets. The battlefield is the ability to run Windows applications on a Mac OS X desktop. But could it have wider ramifications for the enterprise?

It's arguably the first time that VMware, by far and away the dominant virtualisation vendor, has faced direct competition. For sure, in the server business there are plenty of other vendors offering virtualisation technology such as XenSource, SWsoft -- which owns Parallels -- Virtual Iron and others.

In the enterprise space, VMware has had the market to itself, with the other vendors hardly registering on the sales charts. That's not to say that Xen et al aren't deployed in enterprises, especially since Xen is now bundled into the Linux kernel. However, every survey shows that IT departments overwhelmingly base their enterprise infrastructure on VMware products.

On the desktop, things aren't so clear-cut. In the enterprise, there are strong signs that IT managers are considering, piloting and in some cases implementing a desktop virtualisation strategy. This will save them hardware maintenance and asset tracking costs, and allows greater central management control along with the issuing of standard desktop images to task workers, each of which is interchangeable and so easily vaped if it gets infected with malware.

The technology usually consists of several VMs running on a blade or rack server in the data centre, and accessed over network using RDP or other remote access technology.

In some cases, there's a one-to-one relationship between the hardware and the user, with the aim being not so much to reduce the volumes of hardware to be managed, but to reduce the heat output of high-powered workstations in the workplace. Typical applications are financial trading floors and design companies; IBM has just released a hardware product aimed at this very market, the HC10.

But when it comes to running different OSes on one desktop computer, it's the Mac that's proved the hardest nut to crack, simply because Apple maintains its dead hand of control over the hardware and operating system. You could argue that Apple's control-freakery makes Microsoft look positively open source.

As a result, you can't run the Apple Mac OS on anything other than Apple hardware, because OS X, though Unix-based, won't boot unless it detects an Apple boot ROM, which remains proprietary code.

This situation looks highly unlikely to change, as it would involve a fundamental shift in a strategy that Apple has clung to despite requests over the last 20 years from users, analysts and other observers to do so. And today, Apple sees its Intel-based hardware's ability to run Windows as a key incentive for PC users to switch to its platform, and so lock them into its environment. Virtualising OS X on a PC? It ain't gonna happen.

You can however, run Microsoft Windows on an Intel-based Mac, using either Boot Camp, Apple's dual-boot system, or using virtualisation. The former will be bundled free with the next rev of the Mac OS, codenamed Leopard.

But far more useful for users will be either VMware or Parallels' virtualisation technology.

In a per-feature comparison, the two products, Fusion and Desktop for Mac 3.0, stack up fairly closely together. They cost the same at US$79.99, both support snapshots so you can roll a VM back if something goes wrong, and both offer a form of 3D graphics support. For example, Fusion enables users to run DirectX 8.1 applications and play select DirectX 8.1 games from within Windows XP virtual machines. It doesn't support the Vista Aero interface however.

But the key, one suspects, for Mac users, will be how well desktop application integration works. It's a feature that both companies' products offer, and allows users to run Windows applications directly on the desktop as if they were native Mac OS X applications, with no need to use a Windows desktop. Integration includes the ability to cut and paste data between the two systems.

It'll be interesting to see how well they do, with Parallels for once having a nose in front: its product is available now, while VMware Fusion won't be along for a couple of months.

For IT managers, there could be a number of ramifications to this development. It might open the discussion in the minds of the CIO and above as to whether the company should consider switching to Macs as a standard desktop platform, since any essential Windows applications can run on the Mac. Yes, it's a closed platform but that means there's only one place to point the finger. In theory, it could reduce your desktop asset maintenance costs -- although Apple's reputation for support is not great.

There's another potential issue for the longer term. You probably haven't had to run too many training courses recently that show users how to work a PC, since most use one at home. What happens if users buy Macs in droves for their homes? Will they become PC-illiterate?

Stranger things have happened...