Needlebase provides a point-and-click interface for extracting structured information from web pages. As a user, you select elements on an example page that contain the data you’re interested in, and the tool then uses the patterns you’ve defined to pull out information from other pages on a site with a similar structure. For example, you might want to extract product names and prices from a shopping site. With the tool, you could find a single product page, select the product name and price, and then the same elements would be pulled for every other page it crawled from the site. It relies on the fact that most web pages are generated by combining templates with information retrieved from a database, and so have a very consistent structure.
Once you’ve gathered the data, it offers some features that are a bit like Google Refine’s for de-duplicating and cleaning up the data. All in all, it’s a very powerful tool for turning web content into structured information, with a very approachable interface.