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.
RuStem is a fast Ruby module with the the Porter stemming algorithm (a process for removing the commoner morphological and inflexional endings from words in English; its main use is as part of a term normalisation process that is usually done when setting up Information Retrieval systems).
FormValidator is a Ruby port of Perl's Data::FormValidator library. It makes it easy to validate data coming in from HTML forms by providing a robust set of methods to handle required fields, dependent fields, filtering, constraints, tainting, and defaults. Its modular design allows you to easily add your own filters and constraints and also lets you to keep validation data outside of your CGI scripts.
Ruby PHP Serializer is a Ruby module providing workalikes of PHP's serialize() and unserialize() functions, enabling it to manipulate serialized PHP data structures. It supports Array, Hash, String, Fixnum, Float, NilClass, TrueClass, FalseClass, and Struct, and has some support for arbitary object handling.
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.
deplate converts wiki-like markup to LaTeX (standard classes, koma, dramatist, sweave), HTML/PHP (single page, chunked/website, HTML, or s5-based slideshow), DocBook (article, book, man/ref page), and really plain text. Currently supported input formats are viki and Ruby's rdoc. The viki markup supports footnotes, citations, index, table of contents, embedded LaTeX for mathematics, integration with R for dynamically generated figures and tables, and more. Output can be customized via page templates.