flex.rb is a regexp matching and scanning library for the Ruby language. It is more than 3 times faster than Ruby regexps, and supports matching text arriving in multiple parts (via async, non-blocking I/O). flex.rb embeds the GNU Flex 2.5.4 (fast lexical analyzer generator) as an engine, and all of Flex's functionality is accessible from Ruby scripts.
quote.rb is a Ruby script which defines more than 70 quoters (basic string manipulation routines). Most quoters just add or remove backslashes at the appropriate place; others include hexdumps, checksums, simple encryptions, etc. quote.rb's main goal is to provide all quoters necessary for simple and advanced web programming (CGI and server-side scripting) in one place.
pRuby is the ultimate glue code between PHP and Ruby which lets you use Ruby as a HTML-embedded, server-side scripting language. With pRuby, you can intermix PHP and Ruby to create dynamic web content. It features better startup speed than CGI and PHP, better execution speed than PHP, more powerful and less messier to program than PHP, cross-language function calls, and cross-language error handling.
QuantLib is a cross-platform, quantitative finance C++ library for modeling, pricing, trading, and risk management in real-life. It is also wrapped as Python/Ruby/Scheme modules. Extensions for Excel, R, and Mathematica are available. Other such extensions are under consideration. QuantLib offers tools that are useful both for practical implementation and for advanced modeling. It features market conventions, yield curve models, solvers, PDEs, Monte Carlo (low-discrepancy included), exotic options, VAR, and so on.
ruby-tmpl is used for the online and offline creation of HTML, XML, and email documents. Like many other templating languages, ruby-tmpl lets you abstract the presentation from the actual content of a document. However, unlike other templating languages, ruby-tmpl also lets you perform offline processing of documents so that you can have your Web server serve static content created by templates as well as dynamic content. The templating language itself is fully XML-compliant and can safely be embedded in XML documents.