Tokenizing, lexinf and parsing Ruby regular expressions

https://github.com/ammar/regexp_parser

Display which property value regexp support

https://github.com/jaynetics/regexp_property_values

Alternative GNU Readline or Editline implementation by pure Ruby

https://github.com/ruby/reline

Maps Ruby objects to documents and back

https://github.com/trailblazer/representable

Simple Simple HTTP and REST client for Ruby

https://github.com/rest-client/rest-client

Simple Simple HTTP and REST client for Ruby

https://github.com/rest-client/rest-client

Simple DSL to retry failed code blocks

https://github.com/kamui/retriable

Allow for retrying of code blocks

https://github.com/nfedyashev/retryable

Convert html code into markdown

https://github.com/xijo/reverse_markdown

XML toolkit for Ruby

https://github.com/ruby/rexml

Provides access to Amazon EC2, S3, SQS, and SDB web services

https://github.com/rightscale/right_aws

Provides Ruby access to the Flexiscale API

https://github.com/rightscale/right_flexiscale

Provides Ruby access to the GoGrid API

https://github.com/rightscale/right_gogrid

Persistent HTTP/HTTPS connections with error retries

https://github.com/rightscale/right_http_connection

Provides Ruby access to the Slicehost API

https://github.com/rightscale/right_slicehost

Fast and smart autolinking drop-in replacement for Rails auto_link

https://github.com/vmg/rinku

Builds manuals

https://rtomayko.github.io/ronn/

Ruby library for generating one time passwords

https://github.com/mdp/rotp

Simple, easy-to-extend drop-in replacement for pygments

https://github.com/jneen/rouge

Simple, easy-to-extend drop-in replacement for pygments

https://github.com/jneen/rouge

Simple, easy-to-extend drop-in replacement for pygments

https://github.com/jneen/rouge

Ruby library for encoding QR Codes

https://github.com/whomwah/rqrcode_core

Behaviour Driven Development in Ruby

https://rspec.info/ https://github.com/rspec/rspec/tree/main/rspec https://github.com/rspec/rspec

RSpec Core provides the structure for writing executable examples

https://rspec.info/ https://github.com/rspec/rspec/tree/main/rspec-core https://github.com/rspec/rspec

Rspec-expectations adds should and should_not to every object

https://rspec.info/ https://github.com/rspec/rspec/tree/main/rspec-expectations https://github.com/rspec/rspec

Rspec-mocks provides a test-double framework for rspec

https://rspec.info/ https://github.com/rspec/rspec/tree/main/rspec-mocks https://github.com/rspec/rspec

Support utilities for RSpec gems

https://rspec.info/ https://github.com/rspec/rspec/tree/main/rspec-support https://github.com/rspec/rspec

Ruby rsync library

https://github.com/jbussdieker/ruby-rsync

RT into HTML and plain text converter

https://rubygems.org/gems/rttool

Ruby Interface to the GraphViz Graphing Tool

https://github.com/glejeune/Ruby-Graphviz

Pure-ruby growl notifier

https://github.com/drbrain/ruby-growl

MySQL connector in pure ruby

https://gitlab.com/tmtms/ruby-mysql

OpenID library written in pure Ruby

https://github.com/openid/ruby-openid

Progressbar library for Ruby

https://github.com/jfelchner/ruby-progressbar

Pure Ruby implementation of the RC4 algorithm

https://github.com/caiges/Ruby-RC4

SAML toolkit for Ruby on Rails

https://developers.onelogin.com/saml/ruby https://github.com/SAML-Toolkits/ruby-saml

Ruby interface to termios

https://github.com/arika/ruby-termios

Binding for the vips image processing library

https://github.com/libvips/ruby-vips

Yadis Service discovery library written in pure Ruby

http://www.openidenabled.com/yadis/libraries/ruby/

Shim library for Module#ruby2_keywords

https://github.com/ruby/ruby2_keywords

Message creator and parser for the SMB protocol family

https://github.com/rapid7/ruby_smb

Inline::C allows you to embed C/Ruby directly in ruby scripts

https://www.zenspider.com/projects/rubyinline.html

Message creator and parser for the NTLM authentication

https://github.com/WinRb/rubyntlm

Translates ASCII into smart typographic punctuation HTML entities

https://github.com/jmcnevin/rubypants

Simple Twitter library

https://github.com/jugyo/rubytter

Ruby module for reading and writing zip files

https://github.com/rubyzip/rubyzip

Ruby module for reading and writing zip files

https://github.com/rubyzip/rubyzip

EC2 deployment tool

http://solutious.com/projects/rudy/

Safely run SSH commands on a bunch of machines at the same time

https://github.com/delano/rye/

Sass is an extension of CSS3

https://sass-lang.com/