The U.K.-based OpenStreetMap (OSM) mapping data is collected by volunteers using GPS devices to record their movements as they drive, cycle or walk along all the roads in a particular area.
OSM's Web site has the same layout and background as Wikipedia pages because it uses MediaWiki, free wiki software wiki originally written for Wikipedia. OSM, however, is not a project of the Wikimedia Foundation, which is the parent organization of Wikipedia.
OSM was started two years ago by London programmer Steve Coast because of the legal and technical restrictions on the use of or those of the Ordnance Survey, Britain's national mapping agency.
"Google buys commercially restricted data," he said. "It can't make that available for free."
Coast's gripe is that in most countries' mapping is done by government agencies that make money from that data by selling it back to businesses and the public--apart from the U.S. where it must be made available for free.
to collect and upload the GPS data that creates the maps. There are more than 3,600 contributors doing around 50 uploads a day. OSM also throws regular "mapping parties" where people descend on a particular area to map it over a weekend.
Recent areas in the U.K. that have been mapped by volunteers include the Isle of Wight, the county of Rutland, the Surrey Hills and urban areas such as Bath and Reading. Once the raw GPS data is uploaded it can also be edited wiki-style by others, who can add information such as street names.
Coast said: "Allowing people to edit it over the Web is just the obvious thing to do."
OSM asserts it will have the U.K. mapped by the middle of 2008, "if not sooner," and it is also making inroads into Europe where parts of cities such as Copenhagen have been mapped.
"The idea is to do the whole planet," Coast said. "There will be a free map of the planet available. It's going to happen."
OSM has also been attracting interest from commercial users. And London-based Nestoria has started using OSM mapping data for its online property-search service in the Isle of Wight.
Access to postcode, or postal code, data is a more contentious issue as the Royal Mail owns the rights to the U.K.'s postcode database. But Coast is also involved in a project called "Free the Postcode," which would provide the information for free.
He said: "We don't have to get every single one of the 1.9 million postcodes in the U.K., but if we can get to (a density of) 50 or 100 meters or something like that, it becomes useful to a lot of people."
The Ordnance Survey, which derives much of its revenue from selling mapping data to commercial partners, said there is room for both models in the market. It is also trying out a plan to open up some of its secret code to allow software developers to create mapping mashups.
Ed Parsons, chief technology officer at the Ordnance Survey, said: "There will always be a market for closed-source data. I think the two will coexist. I could easily see (Ordnance Survey) making use of open-source data or providing open-source data. We are not closing our eyes. There will be the person who wants to create maps for the parish council, but the utilities, for example, won't use open-source data."
Andy McCue of Silicon.com reported from London