4Sports is an exercise management application. You can use it to analyze your exercises in a number of ways. 4Sports can import data from the Garmin "Forerunner 201/301" devices, and can display some information in a table and in a graph (like heart rate over distance). It's also possible to export the tracks (GPS data) into Google Earth, where the track is color-coded according to your heart-rate. The graphs can be exported to SVG files.
The Mechanize library is used for automating interaction with websites. It automatically stores and sends cookies, follows redirects, can follow links, and submits forms. Form fields can be populated and submitted. Mechanize also keeps track of the sites you have visited as a history.
DM Jot aims to provide a quick and dirty way for Dungeons & Dragons Dungeon Masters (DMs) and players to keep each other in the know about their characters. DMs create campaigns, and players can then create their player characters under those campaigns. Ability scores, skills, and other vital statistics can be entered using an easy and quick interface.
AJAX Tree Control is a modified version of SilverStripe's tree control. It adds dynamic loading of child nodes via AJAX. The default implementation uses the prototype library to make dynamic requests, but this behavior can be overridden by setting functions on the global Tree object. There are a few demo Ruby on Rails applications included in the distribution that show how to use and customize the tree.
Tmpf is tiny script (written in Ruby) to write standard output to a temporary file, run an application with the name of that file as an argument, then delete the temporary file when done. This is useful when you want to pipe output to a program that only accepts files, not standard input. Example: cat myfile.ps | tmpf gv (equivalent to: gv myfile.ps). Despite the incredible simplicity of this script, there is nothing quite like it provided among the standard Unix tools.