Over 400 schools have registered for a free StarOffice licence in the past three months and Sun Microsystems claims that if every school switched from Microsoft Office they would save £48m.
Around a third of those that registered have now decided to do a wider rollout of the software.
Sun estimates that one to two per cent of UK schools currently use the StarOffice suite, and suggested that the push could increase the figure to 20 per cent within 18 months.
"The cost argument is important because schools don't have to upgrade to the latest software and hardware," David Stephenson, business development manager at Sun, told vnunet.com.
"We're not looking for world domination here. We are looking to promote a choice."
Feedback from education institutions on the StarOffice download website indicate an average saving of £2,000 per school, which would translate into £48m across the country, according to Sun.
One educational establishment, which has switched over many of its machines to StarOffice, is Sandwich Technology School in Kent.
Dominic Stevenson, director of ICT at the school, said: "Skills learnt on Microsoft Office are easily transferable to StarOffice and we have already been able to reallocate over £40,000 in funds by switching."
Microsoft's school licences for Office range from £35 to £80 per computer, but Stephen Uden, group manager for education relations at Microsoft, argued that cost is not the only issue for schools.
"We welcome the fact that schools have a choice, but it is not just about cheapest is best," he said. "And we offer pretty substantial discounts to education of up to 80 per cent anyway."
Microsoft came under fire last year from Bob Blizzard MP and schools in his Suffolk constituency about its schools licensing policy.
Blizzard claimed that schools with large numbers of PCs were unable to get discounts available to colleges and universities.
The Department for Education and Skills was unavailable for comment.
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