GeoToad is a geocaching query tool to help speed up the boring part of geocaching: choosing the cache and collecting the data. It allows you to generate any kind of complex query you want, and the program will go and poll the Geocaching query, grab the data, and output it to any format you want. The Geocache info can be synced straight to your GPS, iPod, PDA, or cell phone in over 20 different formats.
ProcPile is a pure Ruby distributed computing cluster environment. Its goal is to allow fast prototyping on smaller datasets, especially those where serialization and deserialization are minor expenses relative to the core processing task. Once the algorithms are settled, you should be able to scale out to full production usage. At that point, you can replace the core processes with Ruby modules written in C (or Inline::C), or move the design to a more "grown-up" clustering environment.
The FIX message viewer is a set of Ruby scripts that parse FIX (Financial Information eXchange protocol) messages to display them in a more human-readable format. The viewer can only parse FIX messages in a file or from STDIN. It also expects a full FIX message on each line. The FIX message can be prepended with a timestamp, but this will be ignored. The output is colored to make it easier to read, and the MsgType field is highlighted. The log viewer works on the command line only, and requires that Ruby is installed.
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.
RubyTree is a simple to use general purpose tree data structure implementation in Ruby. It provides easy access methods for navigating the hierarchy, as well as for accessing the nodes. It also provides ability to marshal the entire tree structure. The library provides a generic tree as well as a binary tree implementation. It is available as a RubyGem or standard Tar/ZIP packages.