DbCharmer is a Rails plugin (and gem) that could be used to manage AR model connections, implement master/slave query schemes, sharding and other magic features many high-scale applications need.

Flapjack is a distributed monitoring notification system that provides a scalable method for processing streams of events from Nagios and deciding who should be notified

Fluentd plugins for the Stackdriver Logging API, which will make logs viewable in the Stackdriver Logs Viewer and can optionally store them in Google Cloud Storage and/or BigQuery. This is an official Google Ruby gem.

Ruby gem generating thumbnail images from a given URL.

Run test/unit tests by line number. Metal!

Wrapper objects which encapsulate measurements and their associated units in Ruby.

Data migrations for Mongoid in Active Record style, minus column input.

PayPal Express Checkout API Client for Instance, Recurring and Digital Goods Payment.

Active Record (>=3.0) plugin which allows you to hide and restore records without actually deleting them. Check its GitHub page for more in-depth information.

Making callback tests easy on the fingers and eyes

Allows identical sidekiq jobs to be processed with a single background call

Terjira is interactive and easy to use command line interface (or Application) for Jira. You do not need to remember resource key or id. Terjira suggests with interactive prompt.

Terraspace: The Terraspace Framework

Rack middleware to remove invalid UTF8 characters from web requests.

acts_as_api enriches the models and controllers of your app in a rails-like way so you can easily determine how your XML/JSON API responses should look like.

Background worker to send Apple Push Notifications over a persistent TCP socket. Includes Resque tweaks to allow persistent sockets between jobs, helper methods for enqueueing APN notifications, and a background daemon to send them.

Beanstalk background job processing made easy

An XMPP DSL for Ruby written on top of EventMachine and Nokogiri

Ruby Comma Seperated Values generation library

Terminal Automation to get you on your projects quickly