Command-line interface on BioRuby

https://github.com/bioruby/bioruby-shell

Facilitate programmatic generation of XML markup

https://github.com/tenderlove/builder

Tool that manages gem dependencies for Ruby applications

https://bundler.io/

Support for the Common Gateway Interface protocol

https://github.com/ruby/cgi

Modern concurrency tools for Ruby

https://github.com/ruby-concurrency/concurrent-ruby

Gems for cool.io

https://github.com/tarcieri/cool.io

Interface to CSV files and data

https://github.com/ruby/csv

Distributed object system for Ruby

https://github.com/ruby/drb

Fluentd plugin to include format values into json, tsv or csv

https://github.com/tagomoris/fluent-mixin-plaintextformatter

Fluent plugin which provides directives for loop extraction

https://github.com/tagomoris/fluent-plugin-config-expander

Gems for fluent plugin of alternative implementation of out_file

https://rubygems.org/gems/fluent-plugin-file-alternative

Gems for fluent plugin to read whole line into single key

https://github.com/yteraoka/fluent-plugin-tail-asis

Fluent event collector

http://fluentd.org/

GDSII reader and writer

http://rubyforge.org/projects/gdsii/

Fast, Enjoyable HTML Parser for Ruby

https://github.com/hpricot/hpricot

Simple callback-based HTTP request/response parser

https://github.com/tmm1/http_parser.rb

New wave Internationalization support for Ruby

https://github.com/ruby-i18n/i18n

iconv wrapper library

https://github.com/ruby/iconv

Gems for iobuffer

https://github.com/tarcieri/iobuffer

Simple logging utility for outputting messages

https://github.com/ruby/logger

Parser / Dumper for LTSV

https://github.com/condor/ltsv

Library for handling money and different currencies

http://rubymoney.github.io/money/

Gems for MessagePack

https://msgpack.org/

Framework-agnostic way to render logic-free views

https://github.com/mustache/mustache

YAML parser and emitter

https://github.com/ruby/psych

Fast Markdown converter for ruby based on discount

https://dafoster.net/projects/rdiscount/

RDoc produces HTML and command-line documentation for Ruby projects

https://ruby.github.io/rdoc/

Builds manuals

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

Framework to implement robust multiprocess servers

https://github.com/treasure-data/serverengine

Setup signal handler which dumps backtrace of running threads

https://github.com/frsyuki/sigdump

Pseudo IO class from/to String

https://github.com/ruby/stringio

Fast strptime engine

https://github.com/nurse/strptime

Ruby utilities for exporting SVN repo to git

https://github.com/nirvdrum/svn2git

Thread-safe collections and utilities for Ruby

https://github.com/ruby-concurrency/thread_safe

Daylight-savings aware timezone support for Ruby

https://tzinfo.github.io/

IANA Time Zone database for TZInfo

https://tzinfo.github.io/

Daylight-savings aware timezone support for Ruby

https://tzinfo.github.io/

Provide classes to handle Uniform Resource Identifiers

https://github.com/ruby/uri

HTTP server toolkit

https://github.com/ruby/webrick

Streaming JSON parsing and encoding library for Ruby

https://github.com/brianmario/yajl-ruby

Fast program launch menu for X Window System

http://www.boomerangsworld.de/cms/tools/runner.html

Restricted User SHell, providing limited remote access to resources

https://puszcza.gnu.org.ua/software/rush/

Language with a focus on memory safety and concurrency

https://www.rust-lang.org/

Experimental Rust compiler front-end for IDEs

https://rust-analyzer.github.io/

Language with a focus on memory safety and concurrency (FreeBSD version)

https://www.rust-lang.org/

Generate Rust bindings from C (and some C++) code

https://github.com/rust-lang/rust-bindgen

Generate C bindings from Rust code

https://github.com/eqrion/cbindgen

Language with a focus on memory safety and concurrency

https://www.rust-lang.org/

Language with a focus on memory safety and concurrency

https://www.rust-lang.org/

FFI bindings for the rustls TLS library

https://github.com/rustls/rustls-ffi