Cache and memory benchmarking tool

http://alasir.com/software/ramspeed/

Experimental range library for C++11/14/17

https://github.com/ericniebler/range-v3

Lightweight web browser using WebKit browser engine

https://github.com/midnightbsd/raphael

Fast JSON parser/generator for C++ with both SAX/DOM style API

https://github.com/Tencent/rapidjson

RDF Parser Toolkit for Redland

http://librdf.org/raptor/

Mount RAR archives as file system

https://hasse69.github.io/rar2fs/

OMF help system based on the Freedesktop specification

https://rarian.freedesktop.org/

High-level interface for RDF

http://librdf.org/

Simple window manager with no fat library dependencies

http://www.nongnu.org/ratpoison/

Fast and safe AV1 encoder

https://github.com/xiph/rav1e

Distributed, collaborative, spam detection and filtering network

http://razor.sourceforge.net/

Unix incarnation of the plan9 shell

https://github.com/rakitzis/rc

Checks rc scripts for style and common errors

https://github.com/crees/rclint

Sync files to and from various cloud services

https://rclone.org/

Version control system (as was in FreeBSD prior to removal)

http://www.gnu.org/software/rcs/

RDP client for Windows NT/2000/2003 Terminal Server

http://www.rdesktop.org/

Fast C++ regex library

https://github.com/google/re2

Compile regular expression to C (much faster final code than flex)

http://re2c.sourceforge.net/

Library for editing command lines as they are typed

http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html

Kernel driver for Realtek PCIe Ethernet Controllers

https://github.com/alexdupre/rtl_bsd_drv

Kernel driver for Realtek PCIe Ethernet Controllers

https://github.com/alexdupre/rtl_bsd_drv

Build-tool for Erlang that follows OTP principles

https://github.com/rebar/rebar

Build tool for Erlang

https://www.rebar3.org/

Converts files between character sets and usages

http://www.gnu.org/software/recode/recode.html

Record desktop sessions to an Ogg-Theora-Vorbis file

http://recordmydesktop.sourceforge.net/

Persistent key-value database with built-in net interface

http://redis.io/

Persistent key-value database with built-in net interface

https://redis.io/

Persistent key-value database with built-in net interface

https://redis.io/

Persistent key-value database with built-in net interface

https://redis.io/

High-level interface for RDF

http://librdf.org

Adjusts the color temperature of your screen

http://jonls.dk/redshift/

Microsoft .Net Portable Class Library Reference Assemblies

https://blogs.msdn.microsoft.com/dotnet/2013/10/14/portable-class-library-pcl-now-available-on-all-platforms/

GTK Remote Desktop Client (lite flavor)

https://www.remmina.org/

Graphical interface to rdesktop

http://gap.nongnu.org/remotedesk/index.html

Controller and GCode generator for RepRap 3D printers

https://reprap.org/wiki/RepSnapper_Manual:Introduction

Fast, secure, efficient backup program

https://restic.github.io

Uncompile an rgb color-name database

https://gitlab.freedesktop.org/xorg/app/rgb

Utility and library for computing and checking of file hashes

http://rhash.anz.ru/

Audio player for GNOME

https://wiki.gnome.org/Apps/Rhythmbox

Rime Array input schema support

https://github.com/rime/rime-array

Rime Chewing schema support

https://github.com/rime/rime-bopomofo

Rime Cangjie v5 schema support

https://github.com/rime/rime-cangjie

Rime Cantonese (Jyutping) schema support

https://github.com/rime/rime-cantonese

Rime Combo Pinyin schema support

https://github.com/rime/rime-combo-pinyin

Rime data files full set

https://github.com/rime/plum

Rime Double Pinyin schema support

https://github.com/rime/rime-double-pinyin

Rime emoji suggestions support

https://github.com/rime/rime-emoji

Essay - the shared vocabulary and language model for Rime

https://github.com/rime/rime-essay

Rime IPA schema support

https://github.com/rime/rime-ipa

Rime Jyutping (old) schema support

https://github.com/rime/rime-jyutping