Ordnance Survey is making its map data available to all web users for free.
The OS OpenData scheme is being launched by Communities Secretary John Denham today in a bid to attract "a new wave of entrepreneurs" to use the data in innovative ways.
Previously, Ordnance Survey information was only available under the OS OpenSpace scheme.
Although the data was free, there were restrictions on who could access the information.
However, the new scheme, which is part of the 'Making Public Data Public' initiative that was launched by Gordon Brown in November last year, ensures the OS data is available to everyone.
"Greater openness, accountability and transparency in Government will give people greater choice and make it easier for individuals to get more directly involved in issues that matter to them," said Denham.
"It will help people make fuller use of other government data on data.gov.uk, as well as stimulating innovation in mapping itself."