ActiveShipping is a unified Ruby API (quite useful on Rails) for shipping information from multiple carriers. It calculates shipping, handling, finds the best price from multiple sources, etc. It is primarily focused on rate requests, but may be extended to cover other aspects of shipping as well. Currently, it includes UPS and USPS modules, and modules for Fedex and DHL are coming soon.
AffirmIt! is a supportive testing framework for Ruby. It tolerates all code, whether it exhibits behavioral challenges or not. It never uses the words "test" or "failure", which would imply a value judgment, or "assertions," which would imply an absolute truth. Instead, it treads softly around code and espouses preferences.
The Atom Publishing Protocol framework for Ruby aims to simplify the implementation of Atom Publishing Protocol (APP) support in Web applications. It achieves this by implementing a framework that handles the protocol-level duties for the programmer, while not making any requirements for the site design.
Berkeley DB XML is a native XML database engine for use within your product. Made available as a C++ library with language bindings for Java, Perl, Python, PHP, and Tcl, it integrates directly into your application (it is not a standalone database server). It provides XQuery access into a database of document containers. XML documents are stored and indexed in their native format using Berkeley DB as the transactional database engine.
Binary Puzzle Solver in Ruby is an automated solver for Binary Puzzles (a kind of logic game) featured on http://www.binarypuzzle.com/. The solver contains an API and a commandline program and explains why it thinks the player should place a 0 or a 1 in the box. Although it contains only a subset of the moves the authors could think of and does not use backtracking, it was able to solve all the puzzles from binarypuzzle.com which the authors tried.
BitNami RubyStack provides a fast, easy way to develop and deploy Ruby on Rails applications. It includes Ruby, Subversion, MySQL, SQLite, ImageMagick, and several Ruby Gems, and will optionally install Apache 2.2 with rewrite and proxy support. It supports Windows, Linux, and OS X, so you can share the same Rails environment on multiple platforms.
Daemonize is a Ruby module derived from Perl's Proc:: Daemon module. It allows you to easily modify any existing Ruby program to run as a daemon. Converting a program to a daemon by hand is a relatively simple process; however, this module will save you the effort of repeatedly looking up the procedure, and it will also ensure that your programs are daemonized in the safest and most correct fashion possible.