It's not just the absence of licence fees that can save you money with open source software - it's also the reliability, the speed of deployment and the ability to build comprehensive solutions.

Our favourite example is that of a mid-sized services company with 120 employees spread across several offices. As a division of a large PLC, they had been paying four hundred thousand pounds a year to a large, not-very-responsive IT outsourcing company using proprietary software.

They were spun off to become an independent company and decided to build their own, entirely open source, infrastructure.

The total costs in the first year for hardware, personnel, project implementation and support came to under two hundred thousand pounds and the ongoing costs from the second year onwards were less than eighty thousand pounds per year - an annual saving of over 75%. On top of this their new systems proved orders of magnitude faster and more reliable.