The Ruby Standard Library is a vast collection of classes and modules that you can require in your code for additional features.
Below is an overview of libraries and extensions followed by a brief description.
Calculates a set of unique abbreviations for a given set of strings
Support for encoding and decoding binary data using a Base64 representation
Provides methods to measure and report the time used to execute code
Support for the Common Gateway Interface protocol
Debugging functionality for Ruby
Provides three abilities to delegate method calls to an object
Distributed object system for Ruby
Require 'English.rb' to reference global variables with less cryptic names
An easy to use but powerful templating system for Ruby
This module supports top-down traversal of a set of file paths
Parse command line options similar to the GNU C getopt_long()
Module used to generate a Makefile for C extensions
Provides an object or module to use safely by more than one thread
Support for the File Transfer Protocol
HTTP client api for Ruby
Ruby client api for Internet Message Access Protocol
Ruby client library for POP3
Simple Mail Transfer Protocol client library for Ruby
Provides a mechanism for publish/subscribe pattern in Ruby
An easy-to-use wrapper for Net::HTTP, Net::HTTPS and Net::FTP
Provides access to stdin, stdout and stderr when running other programs
Ruby-oriented class for command-line option analysis
Provides a PrettyPrinter for Ruby objects
Implements a pretty printing algorithm for readable structure
Implements a file based persistence mechanism based on a Hash
Information of your configure and build of Ruby
Replace Socket DNS with Resolv
Thread-aware DNS resolver library in Ruby
The Linda distributed computing paradigm in Ruby
Package management framework for Ruby
Interface for secure random number generator
Provides a class to deal with collections of unordered, unique values
Manipulates strings with word parsing rules of UNIX Bourne shell
Implementation of the Singleton pattern for Ruby
A utility class for managing temporary files
Extends the Time class with methods for parsing and conversion
Auto-terminate potentially long-running operations in Ruby
Extends the Dir class to manage the OS temporary file path
Topological sorting using Tarjan's algorithm
Utilities to replace common UNIX commands
A Ruby module providing support for Uniform Resource Identifiers
Allows a referenced object to be garbage-collected
Ruby client library for the Psych YAML implementation
Provides coverage measurement for Ruby
Provides a framework for message digest libraries
Extensions for Ruby IO class, including wait and ::console
Ruby extension for Network Kanji Filter
Extends ObjectSpace module to add methods for internal statistics
Representation of the name of a file or directory on the filesystem
Creates and manages pseudo terminals
Provides an interface for GNU Readline and Edit Line (libedit)
Provides an interface for parsing Ruby programs into S-expressions
Access underlying OS socket implementations
Ruby interface for the POSIX system logging facility
Provides an interface for OLE Automation in Ruby
Manage your Ruby application's gem dependencies
Provides an interface to read and write CSV files and data
Module for defining custom exceptions with specific messages
Several file utility methods for copying, moving, removing, etc
Provides delegation of specified methods to a designated object
Provides methods to manipulate IPv4 and IPv6 IP addresses
Interactive Ruby command-line tool for REPL (Read Eval Print Loop)
Provides a simple logging utility for outputting messages
Represents a mathematical matrix.
Mixin to extend objects to be handled like a Mutex
Prime numbers and factorization library
A LALR(1) parser generator written in Ruby.
Produces HTML and command-line documentation for Ruby
An XML toolkit for Ruby
Family of libraries that support various formats of XML “feeds”
Outputs a source level execution trace of a Ruby program
An HTTP server toolkit for Ruby
Provides arbitrary-precision floating point decimal arithmetic
A subclass of Object includes Comparable module for handling dates
Subclass of Date to handling dates, hours, minutes, seconds, offsets
Provides a wrapper for the UNIX-style Database Manager Library
Provides access to information typically stored in UNIX /etc directory
Loads constants defined in the OS fcntl.h C header file
A libffi wrapper for Ruby
Ruby extension for the GNU dbm (gdbm) library
Console interface
Implements Javascript Object Notation for Ruby
Provides SSL, TLS and general purpose cryptography for Ruby
A YAML parser and emitter for Ruby
Provides a simple file-based key-value store with String keys and values
Pseudo I/O on String objects
Provides lexical scanning operations on a String
Ruby interface for the zlib compression/decompression library
“Did you mean?” experience in Ruby
A test suite with TDD, BDD, mocking and benchmarking
Telnet client library for Ruby
Power Assert for Ruby.
Ruby build program with capabilities similar to make
A compatibility layer for MiniTest
Remote Procedure Call over HTTP support for Ruby