A tail(1)-like utility for nginx log files. It supports parsing, filtering and formatting individual log lines.

Merge multiple PDFs in to one using iText's PdfCopyFile.

Easy denormalization for your ActiveRecord models

A plugin/gem that provides access to the Prowl API (http://prowlapp.com). Works with Rails 2 or 3 as well as any other Ruby web frameworks or in your own scripts.

Runs regular Rails/ActiveRecord migrations via the Percona Toolkit pt-online-schema-change tool.

A Ruby wrapper around the DPS-hosted PxPay service

Logs exceptions inside a database table. Now available as gem for Rails3 (previously a plugin for Rails2)

Port of the old, venerable ActsAsTree with a bit of a twist

ActiveRecord-like associations for ActiveResource

Active Record caching and indexing in memcache.

RubiGen - Ruby Generator Framework

A simple to use, yet powerful Ruby framework for building console-based applications.

This is a Ruby API for Fitbit.com, currently scraping, but soon will use the officail API (when released)

Call Lua from Ruby (and Ruby from Lua in Ruby)

ScheduleFu allows scheduling events with dates and times. It includes both the model and view portions of a calendar. It borrow heavily from acts_as_calendar (http://github.com/dball/acts_as_calendar) and calendar_helper (http://github.com/topfunky/calendar_helper).

Integrate SimpleCov results into Atlassian Bamboo CI server

Crops images based on entropy: leaving the most interesting part intact. Usefull for automatic cropping or resizing of images.

SocialPoster is a gem that allows you easily post to different social networks.

Spree Mail extends Spree by adding a mailing list subscriber model, sign up forms and an admin to send messages.

Spree Redirects adds an interface for redirecting old url's to new ones.