Birmingham City Council is converting the PCs used in its 40 libraries to Linux as part of a year-long trial of the open source operating system.
The council - the UK's largest - has commissioned an independent auditor to assess whether the trial demonstrates that using Linux and open source software represents better value than using Microsoft alternatives.
Birmingham is trialling Linux on more than 500 PCs as part of the Office of the Deputy Prime Minister's E-Innovations project to test open source in the public sector.
The PCs will be equipped with the Gnome presentation layer of the Linux operating system, the Openoffice productivity suite and Mozilla's Firefox browser.
The local authority has kept IBM's Lotus Notes 6.5 on the 500-plus desktops because library staff need to remain within the council-wide e-mail system.
Les Timms, Birmingham City Council's IT manager with responsibility for the open source trial, said, "The next phase of the project is to do a detailed study on the cost base, the long-term viability and how it integrates with our existing structure and security."
The IT department chose Linux using the Gnome presentation layer after inviting both library staff and members of the public to try desktops using different operating systems and presentation layers.
Timms said, "We had Mac, Microsoft Windows and best-of-breed open source configurations, including KDE and Gnome. We had 300 people using the PCs. The one they preferred was Gnome."
The Linux trial will run until the end of March 2006.