The Government has officially adopted ODF as the standard format for working on its documents, provoking the ire of Microsoft.
The Coalition announced last night that Open Document Format would be the default for sharing and collaborating on docs, while PDF/A or HTML would be the standard formats for viewing government docs.
The new open standards came into effect immediately, with the Government Digital Service (GDS) tasked with helping departments implement them.
The announcement will come as a blow to Microsoft, which tried to push its own preferred Open XML standard on Whitehall, arguing that open source tools can already handle the format.
Redmond released a statement questioning the value of the move to the British public, but Cabinet Office minister Francis Maude said in a statement the decision was about saving money.
"We have listened to those who told us that open standards will reduce their costs and make it easier to work with government," he said.
"This is a major step forward for our digital-by-default agenda which is helping save citizens, businesses and taxpayers £1.2bn over this Parliament."
GDS exec director Mike Bracken added that an open standard would mean "people won’t have costs imposed on them just to view or work with information from government".
Microsoft had also submitted a written response to Labour’s Digital Review warning the opposition party, which could come into power next May, not to "become too narrow" in its adoption of open standards and not to rule out any products or suppliers.
In an interview this week with shadow Cabinet Office minister Chi Onwurah, she told CBR: "We take the comments on board. They’ve been the dominant desktop supplier for the last many years, but there are new productivity tools coming along now and also new platforms.
"What we want is a mixed economy of suppliers. We want to use open standards to do that."
Both Office 365 and Office 2013 support the ODF format, and Microsoft told CBR that "current and future investments in Office are safe".
But a spokeswoman added: "Microsoft believes it is unproven and unclear how UK citizens will benefit from the government’s decision.
"We actively support a broad range of open standards, which is why (like Adobe has with the PDF file format) we now collaborate with many contributors to maintain the Open XML file format through independent and international standards bodies.
"We also believe that giving users a choice of standards is an important spur to improvement, competition and consequently, innovation. The government’s stated and laudable strategy to be cloud-first in the provision of its services to citizens depends on nurturing, not constraining such innovation."
