ack is a tool like grep, aimed at programmers with large trees of heterogeneous source code.

ack is written purely in Perl, and takes advantage of the power of Perl's regular expressions.

BOSS (Build your Own Search Service) is Yahoo!'s open search web services platform. The goal of BOSS is simple: to foster innovation in the search industry. Developers, start-ups, and large Internet companies can use BOSS to build and launch web-scale search products that utilize the entire Yahoo! Search index. BOSS gives you access to Yahoo!'s investments in crawling and indexing, ranking and relevancy algorithms, and powerful infrastructure. By combining your unique assets and ideas with our search technology assets, BOSS is a platform for the next generation of search innovation, serving hundreds of millions of users across the Web.

The most under-appreciated search engine on the Internet.

The xISBN Web service supplies ISBNs and other information associated with an individual intellectual work that is represented in WorldCat. Submit an ISBN to this service, and it returns a list of related ISBNs and selected metadata.

Pipes is a powerful composition tool to aggregate, manipulate, and mashup content from around the web. Like Unix pipes, simple commands can be combined together to create output that meets your needs: