Debugging toolbar for Rack applications implemented as middleware. Based on logical-insight and rack-bug.

Rack middleware Captcha verification using Recaptcha API.

Tools for monitoring Rack apps in production.

Streaming proxy for Rack, the rainbows to Rack::Proxy's unicorn.

Rack middleware for Weixin apps: message validation/parser/generator

Rack middleware for serving static gzipped assets generated by the Rails asset pipeline

Highly customizable exception handling for Ruby on Rails

A resque plugin for specifying the queues a worker pulls from with wildcards, negations, or dynamic look up from redis

Rack-mountable app to use and configure feature flags via the rollout gem

RubyHome is a lightweight service you can run on your home network that emulates the iOS HomeKit API. It supports community contributed plugins, which are modules that provide a bridge from HomeKit to various 3rd-party APIs provided by manufacturers of smart home devices.

A Sinatra extension for building Shopify Apps. Akin to the shopify_app gem but for Sinatra

Benchmarks for Sidekiq

SPARQL Implements SPARQL 1.1 Query, Update and result formats for the Ruby RDF.rb library suite.

Provides the ability to analyze StackProf dumps

Testbot is a test distribution tool that works with Rails, RSpec, RSpec2, Test::Unit and Cucumber.

Combined events calendar for Google Calendar, iCal, and friends.

Ruby gem and command-line utility for conversion of DOI metadata from and to different metadata formats, including schema.org.

capybara-envjs is a Capybara driver for the envjs gem. It is similar to Capybara's rack-test driver in that it runs tests against your rack application directly but fully supports javascript in your application.

CarrierWave storage for Dropbox

Instead of forcing a methodology, structure, and tons of naming conventions, Draft quickly allows you to get up and running during the early phases of your project and in no way prevents you from moving beyond it when your project becomes bigger.