Image viewer with Xfce integration

https://goodies.xfce.org/projects/applications/ristretto

Flexible message logging facility for C++

https://www.arg0.net/rlog

Roboto typeface family

http://developer.android.com/design/style/typography.html

Fully skinnable XHTML/CSS webmail written in PHP

https://roundcube.net/

Classic skin/theme for Rouncube webmail

https://github.com/roundcube/classic/

Larry skin/theme for Rouncube webmail

https://github.com/roundcube/larry/

Convert .rpm files to cpio format

The RPM Package Manager

https://rpm.org/

Round Robin Database Tools

http://www.rrdtool.org/

Fast spam filtering system

https://rspamd.com/

Restricted Secure SHell only for sftp or/and scp

http://www.pizzashack.org/rssh/index.shtml

Network file distribution/synchronization utility

http://rsync.samba.org/

RTMP streams download utility

http://rtmpdump.mplayerhq.hu/

BitTorrent Client written in C++

https://github.com/rakshasa/rtorrent

Ruby interface to Oracle Berkeley DB revision 2 or later

https://github.com/knu/ruby-bdb

Binary data dumper module for Ruby

http://www.geocities.co.jp/SiliconValley-Oakland/2986/

Package management framework for the Ruby language

https://rubygems.org/

Object-oriented interpreted scripting language

https://www.ruby-lang.org/en/

Object-oriented interpreted scripting language

https://www.ruby-lang.org/en/

Object-oriented interpreted scripting language

https://www.ruby-lang.org/en/

Fast, open source text processor and publishing toolchain

https://asciidoctor.org/

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

Fluent event collector

http://fluentd.org/

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

Gems for iobuffer

https://github.com/tarcieri/iobuffer

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

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

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/