Discount is an implementation of John Gruber's Markdown markup language in C. It implements all of the language described in the markdown syntax document and passes the Markdown 1.0 test suite.

CiteProc is a citation processor interface and citation data API based on the CSL specifications. To actually process citations, a dedicated processor engine is required: a pure Ruby engine is available in the citeproc-ruby gem.

rest-client provides a simple HTTP and REST client for Ruby, inspired by the Sinatra microframework style of specifying actions: get, put, post, delete.

This library implements HTTP's digest authentication scheme based on RFC 2617. This enables the use of the digest authentication scheme instead of the more insecure basic authentication scheme.

BRASS (Bare-Metal Ruby Assertion System Standard) is a basic foundational assertions framework for other assertion and test frameworks to make use of.

Lino provides an interface to run external commands. It provides an interface to add options as well as managing the standard input, output and error streams.

Unicode::DisplayWidth is a Ruby library which can determine the display width of strings in Ruby.

The SafeYAML gem provides an alternative implementation of YAML.load suitable for accepting user input in Ruby applications.

This library provides functionality for retrieving email via POP3, the Post Office Protocol version 3, as specified by RFC1939.

This package provides a RuboCop plugin for Rake.

IRB is an interactive Ruby command-line tool for REPL (Read Eval Print Loop).

This package provides a Ruby module that provides a two-phase lock with a counter.

This package provides a Jekyll plugin to add metadata tags for search engines and social networks to better index and display your site's content.

Asciidoctor PDF is an extension for Asciidoctor that converts AsciiDoc documents to Portable Document Format (PDF) using the Prawn PDF library. It has features such as:

• Direct AsciiDoc to PDF conversion

• Configuration-driven theme (style and layout)

• Scalable Vector Graphics (SVG) support

• PDF document outline (i.e., bookmarks)

• Table of contents page(s)

• Document metadata (title, authors, subject, keywords, etc.)

• Internal cross reference links

• Syntax highlighting with Rouge, Pygments, or CodeRay

• Page numbering

• Customizable running content (header and footer)

• “Keep together” blocks (i.e., page breaks avoided in certain block content)

• Orphaned section titles avoided

• Autofit verbatim blocks (as permitted by base_font_size_min setting)

• Table border settings honored

• Font-based icons

• Custom TrueType (TTF) fonts

• Double-sided printing mode (margins alternate on recto and verso pages)

TTFunk is a TrueType font parser written in pure Ruby. It is used as part of the Prawn PDF generator.

This gem extends ruby-rdf with several common RDF vocabularies.

Yell is a comprehensive logging replacement for Ruby. It defines multiple adapters, various log level combinations and message formatting options.

VersionGem aims to provide introspection of a Version module based on a Version::VERSION constant string wile not interfering with gemspec parsing where the VERSION string is traditionally used.

Nokogiri (鋸) parses and searches XML/HTML, and features both CSS3 selector and XPath 1.0 support.

Multihashes provides a simple, low-level multihash implementation for Ruby. A multihash is a digest with an embedded hash function code

This package provides C extensions to optimize the concurrent-ruby gem when running under the Matz's Ruby Interpreter (MRI, also known as CRuby).

Rouge is a code highlighter written in Ruby. It supports more than 100 languages and outputs HTML or ANSI 256-color text. Its HTML output is compatible with stylesheets designed for pygments.

This Ruby library provides a simple wrapper to bcrypt, a secure hash algorithm for hashing passwords.

This package provides a function to deep freeze Ruby objects.