Ruby/Google offers a higher-level abstraction of Google's SOAP-driven Web API. It allows the user to programatically query the Google search engine from Ruby. The aim of the library is to shield the programmer from the details of the raw data structures returned by the Web API, and in the process make the API more accessible for everyday use.
Ruby/Amazon is a simple Ruby library that allows one to retrieve information from the popular Amazon.com Website via Amazon Web Services v3. It aims to wrap the grunt work of interacting with the Amazon API behind a high-level layer of Ruby and, in so doing, make it easier to use. Ruby/Amazon is succeeded by Ruby/AWS.
index.rb is a general indexing framework for Ruby. With it, you can create collections of documents, then index and search them. The traditional inverted index is supported, as is Latent Semantic Indexing (LSI). Input documents may be stemmed, to make user queries more general. It also provides TextTiling to break input documents covering multiple topics into topic-specific sub-documents.