Once you are in the clouds, it is a long way down. As you are reading IT Brief magazine, it follows that you probably know that much – if not most – of the key infrastructure of the net runs on free, open source software. Major governments and corporations the world over benefit from it, and for much of the world the model of proprietary and closed client/server software, with its forced upgrades and usurious per-seat licences, is finally sliding into the past.

But what of the ‘cloud'? How about SaaS? Where, in regard to the world of open and free, are the virtualisation vendors? Virtualisation businesses such as cloud vendors and suppliers of Software as a Service hope to take your key business functions and base them in the cloud instead of running on your own servers. Much of the cost and headaches associated with running your software will – theoretically – disappear.

At this point, however, most of these virtualisation vendors and cloud shamans are essentially operating proprietary software businesses themselves and, like the old commercial-off-the-shelf world, this is beginning to cause headaches for customers wanting to change services.

Vendor lock-in is alive and well and living in the cloud! There are currently SaaS offerings for most major pieces of software that your business uses. Accounting, CRM, email, ordering, project planning and payroll solutions are offered as cloud-based services and allow a commoditisation of software, where you can simply change your number of users as required and pay as you go, with no need to estimate the number of licences needed and pay for them in advance. This flexibility and reduction in capital expenditure, compared to current commercial software, is luring many businesses of all sizes to the cloud.

For reduction of capital expenditures, though, you can't beat free. All of the above types of applications have free analogues, with open and accessible code that – if it isn't a perfect fit – can be customised to your specification by a knowledgeable vendor, but with no licence fees or seat charges – ever. So there are choices. But alas, there is still no substitute for solid cost modelling.

Let's look at some of the questions you might ask when considering the cloud. Before signing that contract, ask how your data is secured. What formats is it stored in? How do you get your data out? How easy is it to add additional services? How easy is it to migrate your data to another service? Are there special fees for exit migration?

With the flexibility and range of new offerings provided by this upcoming world of clouds and virtual services, don't get tripped up by not being able to easily take advantage of the portability promised by the underlying open technology. Can you leave if, for whatever reason, you wish to discontinue use of a specific cloud or SaaS vendor?

How will your data be exported? In what formats? How fast? Ideally, before signing up to any service, have total confirmation that your company's secure data can be extracted in full, and in an open data standard, at any time and with no extra costs. It's important to make sure your data is stored in open formats, so that even when you have extracted it from the service, you don't require additional licences to translate into something readable.

Currently, changing SaaS services is difficult because in essence you have a series of proprietary clouds that don't really talk to each other. Eventually, you can expect to see large IT shops acting as brokers between all these differing services, but there is no current standard set of operating procedures and governance around cloud computing services, as there is for interactions across the internet.

Carefully check what is included in your service offering compared to what your company actually needs. Make sure that additional services are not at a high cost because the initial offering is a loss leader. Ask directly if the software is open source and under precisely which licence. There is an array of licences and it pays to know exactly what you are allowed to do. Don't forget to find out how your directors feel about key company data living outside the building – or even outside the country – on a vendor's servers.

There are going to be more and more cloud vendors starting to open their services to allow easy transition as the market becomes more mature. At the moment, though, this tends to be tricky at best, and you would be well advised to talk to a trusted IT partner before starting or moving to cloud services.