Enables keyframe-based animations and parameterization.

https://www.qt.io/

Qt6 Remote Objects module

https://www.qt.io/

Qt6 SCXML module

https://www.qt.io/

Qt sensors module

https://www.qt.io/

Qt functions to access industrial bus systems

https://www.qt.io/

Qt functions to access serial ports

https://www.qt.io/

Provides tools for the cross-platform Qt shader pipeline

https://www.qt.io/

Accessibilty features for Qt6

https://www.qt.io/

Qt6 classes for displaying the contents of SVG files

https://www.qt.io/

Qt declarative framework for dynamic user interfaces

https://www.qt.io/

Qt 6 translation module

https://qt-project.org

Qt 6 Virtual Keyboard Module

https://www.qt.io/

Qt6 wrapper for Wayland

https://www.qt.io/

Qt 6 library for integration of C++/QML with HTML/js clients

https://www.qt.io/

Qt implementation of WebSocket protocol

https://www.qt.io/

Qt 6 configuration tool

https://github.com/trialuser02/qt6ct/tags

Qt6 binding for FreePascal

https://wiki.lazarus.freepascal.org/index.php/Qt6_Interface

Secure client uses latest OpenSSL and best encryption

https://centrabit.com/

Tetris like game with multiplayer support

http://code.google.com/p/quadra/

Gnome quadrapassel

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

Quake II data files

http://www.idsoftware.com/games/quake/quake2/

Quake III Arena data files

http://www.idsoftware.com/games/quake/quake3-arena/

Qt/C++ wrapper for ZIP/UNZIP package

https://github.com/stachenov/quazip

Scriptable FTP client

http://quftp.sourceforge.net/

RabbitMQ is an implementation of AMQP

http://www.rabbitmq.com/

RabbitMQ C AMQP client library

https://github.com/alanxz/rabbitmq-c

Compile regular languages into executable C/C++ code

http://www.complang.org/ragel/

Test performance of storage devices

Elegant sans-serif font, designed in a single thin weight

https://www.theleagueofmoveabletype.com/raleway

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/

RDF Parser Toolkit for Redland

https://librdf.org/raptor/

File archiver (binary port)

https://www.rarlab.com/

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

https://www.nongnu.org/ratpoison/

Distributed, collaborative, spam detection and filtering network

http://razor.sourceforge.net/

Unix incarnation of the plan9 shell

http://tobold.org/article/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

Lexer generator for C, C++ and Go with a focus on generating fast code

https://re2c.org/

Library for editing command lines as they are typed

https://tiswww.case.edu/php/chet/readline/rltop.html

Kernel driver for Realtek PCIe Ethernet Controllers

https://www.realtek.com/en/component/zoo/category/network-interface-controllers-10-100-1000m-gigabit-ethernet-pci-express-software