Vagrant is a tool for building and distributing virtualized development environments.

Guard is a command line tool to easily handle events on file system modifications.

Supervisors, Supervision Groups, and Supervision Trees for Celluloid.

Strategies for cleaning databases. Can be used to ensure a clean slate for testing.

Render components in views or controller actions. Server-side rendering powered by ExecJS. Transform JSX in the asset pipeline or use Shakapacker.

Profiling toolkit for Rack applications with Rails integration. Client Side profiling, DB profiling and Server profiling.

Poltergeist is a driver for Capybara that allows you to run your tests on a headless WebKit browser, provided by PhantomJS.

Makes spring watch files using the listen gem.

calabash-android drives tests for native and hybrid Android apps.

The New Relic Ruby agent requires the gem newrelic_rpm, and it includes distributed tracing that uses head-based sampling (standard distributed tracing). If you want distributed tracing to use tail-based sampling (Infinite Tracing), you need to add both newrelic_rpm and newrelic-infinite_tracing...

calabash-cucumber drives tests for native iOS apps. You must link your app with calabash-ios-server framework to execute tests.

Provides support for auto-recompiling Nanoc sites.

Generate bash command line tools using YAML configuration

Rebuild your Jekyll site when a file changes with the `--watch` switch.

Gradual Typing for Ruby

Official LaunchDarkly SDK for Ruby

Be lazy. Let Maid clean up after you, based on rules you define. Think of it as "Hazel for hackers".

Rhodes mobile framework

Shopify CLI helps you build Shopify apps faster. It quickly scaffolds Node.js and Ruby on Rails embedded apps. It also automates many common tasks in the development process and lets you quickly add popular features, such as billing and webhooks.

Restarts your app when a file changes. A no-frills, command-line alternative to Guard, Shotgun, Autotest, etc.