As a global resource built from the spare time of millions of volunteers, Wikipedia may be the epitome of Web 2.0. But the Wikimedia Foundation, a nonprofit organization that runs Wikipedia, among other projects, is now thinking about how to make it a linchpin of Web 3.0, or the semantic Web.

That means making some of the data on Wikipedia's 15 million (and counting) articles understandable to computers as well as humans. This would allow software to know, for example, that the numbers shown in one of the columns in this table listing U.S. presidents are dates. That could, in turn, allow applications that draw on Wikipedia to automatically generate historical timelines or answer the kind of general knowledge questions that would usually entail a person finding and reading a relevant entry on the site.

At the 2010 Semantic Technology conference in San Francisco last month, the foundation's deputy director, Erik Möller, and colleague Trevor Parscal, a user-experience developer for Wikimedia, showed some first steps taken by the foundation to explore how more semantic structure might be added to Wikipedia. They also appealed to the semantic Web community to help develop ways to make Wikipedia's knowledge more accessible to computers and software.