Bristol City Council has calculated that it will save 60 percent, or more than £1m, over the next five years by switching to Sun's StarOffice, rather than Microsoft Office.
The Council estimates that the total cost of StarOffice — Sun's commercial version of the open source OpenOffice.org suite — over a five year period will be £670,000, while Microsoft Office would cost £1.7m, according to the the government-funded Open Source Academy.
The figures take into account the expected cost of migrating, training and supporting 5,500 users for each product.
Bristol Council, which is currently running a mixed environment of Lotus 1-2-3, WordPerfect and Microsoft Office, believes it may even have overestimated the cost of migrating to StarOffice, as the training barrier appears to be lower than was originally thought.
"It was difficult to be certain about some of the costs relating to support and training, so we erred on the pessimistic side, assuming that StarOffice would involve higher costs and that existing Microsoft Office users would not require any training at all," said Gavin Beckett, Bristol City Council's IT strategy manager, in a statement.
"So far, the experience of migrating users has proved that the cost of migration is low and ease of use is high. We now have concrete evidence that less effort is required to deploy the software, support and train users than we estimated."
The main issue the council has faced in migrating users is their reluctance to try new software, according to Beckett.
"Our biggest challenge was encouraging staff to be open-minded about anything that wasn't MS Office. Microsoft has become so dominant and ubiquitous that the default assumption for many people is that everything else is inferior and that the only way to accomplish work is to do it in the exact way that an MS Office product does it. When you combine this with the idea of software that doesn't cost money, you end up with comments like 'if it's cheap it must be nasty,'" said Beckett.
The council has worked towards overcoming this perception by listening to user's concerns and demonstrating what StarOffice can do.
The Open Source Academy, which was launched in April last year, aims to encourage the use of open source software by local authorities. It is funded under the Office of the Deputy Prime Minister's e-Innovations programme.