Virtual machines on servers and desktops alike are coming of age, with VMware's ACE constituting a new front in the technology's development. It helps that Microsoft recently swept away one of the main obstacles -- that is, whether an OS running in a virtualised environment constitutes another iteration and therefore needs another paid-for licence. Clearly, one of the incentives for the Redmond software giant to make this move was concern not to impede sales of its own virtualisation product, Virtual PC.

Virtualisation itself is nothing new -- it's been around since the bad old mainframe days. It's just that, in the PC environment, hardware is now powerful enough to run one or more virtual computers as containers within a host OS with little perceptible overhead. The only real cost, aside from the virtualisation software itself, is the need for as much memory for each virtual machine as a real one would require. Other than that, you save on all the extra hardware and other overheads.

In addition, you gain more control over virtual systems than over real ones, being able to start and stop it easily and quickly, and prototyping applications and configurations without having to reboot your machine or touch live production systems makes life a lot simpler.

Now, with the launch of VMware's ACE, at least one of the company's customers agrees that standardised configurations can be deployed to desktops and other environments more easily. ACE consists effectively of a run-time version of VMware's virtualisation technology that can, for example, can be shipped out to customers without licensing concerns.

One user, Dave Parsons, software development manager for ALG Software, explains how his company has been using the product since the early beta emerged.

"We're a small ISV of just 110 people. We're big workstation users, and the problem we had was doing off-site training with big database applications. If customers don't have the environment that can support the software needed for training, that becomes an issue.

"The problem is that it takes a lot of time to configure the server systems -- we use IIS and SQL Server -- and clients when setting up a complex application. With VMware ACE, we have everything configured and loaded beforehand.

"It also allows us to have the systems back up and running quickly if something crashes and, at the end of the session, we can restore the classroom to its default state quickly."

The idea of using an alternative did occur to Parsons -- the base VMware workstation product.

"But we saw the opportunity that ACE provided. We were thinking about using VMware Workstation but ACE gives you the entire PC in a box. If customers don't have VMware, ACE allows us to create a run-time version and have it run without problems.

"It also has digital rights management in there, so if we forget to de-install, we've set it to expire on specific date - such as five days after the install date, it protects our IP and ensures we don't break the terms of the VMware licence.

"It also means that when we're with working our partners, such as Fujitsu, it allows us to deliver a working system to them with reproducible quality."

Parsons said that couldn't think of any major issues with the product.

"There is an overhead but it's not huge. Disk space can be an issue but XP is only 1.2GB so a 2.5GB image is fine, eve when using products such as SQL Server.

"I can't see downside to it and lots of different people that I know of are using it. The economics are good, as is the fact that it will run on decommissioned equipment. It proved to be a very interesting idea."

With that kind of customer endorsement, the fact that ACE now puts VMware -- now an EMC subsidiary -- two steps ahead of Microsoft is likely to please more than just the product's marketing managers.