Programming the Semantic Web

Chapter 7. Publishing Semantic Data

Publishing semantic data often results in a “network effect” because of the connections that occur between datasets. For example, publishing restaurant data can suddenly open up a new application for a connected geographic dataset. Campaign finance data is made more accessible by its connections to politicians and their voting records. As more semantic data is published, existing semantic data becomes more useful, which in turn increases the scope and usefulness of the applications that can be built.

The main barrier to publishing semantic data has been that many of the standards are complicated and confusing, and there has been a lack of good tools. Fortunately, there have been several efforts to create simpler semantic web standards that make it easier for both designers and developers to publish their data. Another promising trend is that thousands of web applications now have open APIs and are publishing machine-readable data with implicit semantics that can easily be translated to the explicit semantics that we’ve been covering. All of this has led to early efforts by some very large web properties to consume semantic data and use it to enhance their applications.

In this chapter we’ll look at two emerging standards, Microformats and RDFa, that aim to make publishing semantic data far easier for web designers by simply extending the already familiar HTML syntax. We’ll also look at ways to take data that you might already have access to—either ...