Free software programmed in C++

Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and anticipated web standards. The software is available for Windows, macOS, and Linux systems, with unofficial ports for other platforms, as well as a mobile version for Android (see Firefox for Android) and iOS.

free and open-source 3D computer graphics software

OpenOffice.org is an open-source office productivity software suite. It originated from the proprietary StarOffice, developed by Star Division, which was acquired by Sun Microsystems in 1999. Sun open-sourced the software in July 2000 as a free alternative to Microsoft Office, and released OpenOffice.org version 1.0 on 1 May 2002.

LibreOffice () is a free and open-source office productivity software suite developed by The Document Foundation (TDF). It was created in 2010 as a fork of OpenOffice.org, itself a successor to StarOffice. The suite includes applications for word processing (Writer), spreadsheets (Calc), presentations (Impress), vector graphics (Draw), database management (Base), and formula editing (Math). It supports the OpenDocument format and is compatible with other major formats, including those used by Microsoft Office.

Inkscape is a free and open-source software vector graphics editor released under a GNU General Public License (GPL) 2.0 or later. It is used for both artistic and technical illustrations such as cartoons, clip art, logos, typography, diagrams, and flowcharts. It uses vector graphics to allow for sharp printouts and renderings at unlimited resolution and is not bound to a fixed number of pixels like raster graphics.

free and open source email client and personal information manager

Node.js is a cross-platform, open-source JavaScript runtime environment that can run on Windows, Linux, Unix, macOS, and more. Node.js runs on the V8 JavaScript engine, and executes JavaScript code outside a web browser. According to the Stack Overflow Developer Survey, Node.js is one of the most commonly used web technologies.

free and open-source cross-platform web browser

Apertium is a free/open-source rule-based machine translation platform. It is free software and released under the terms of the GNU General Public License.

multi-platform open-source digital audio recording and editing application

optimizing compiler produced by the GNU Project, key component of the GNU tool-chain and standard compiler for most projects related to GNU and the Linux kernel.

object-oriented framework for GUI creation

numerical computation software

QGIS is a geographic information system (GIS) software that is free and open-source. QGIS supports Windows, macOS, and Linux. It supports viewing, editing, printing, and analysis of geospatial data in a range of data formats. Its name comes from an abbreviation of its previous name, Quantum GIS.

Notepad++ (sometimes npp or NPP) is a text and source code editor for use with Microsoft Windows. It supports tabbed editing, which allows working with multiple open files in one window. The program's name comes from the C postfix increment operator.

7-Zip is a free and open-source file archiver, a utility used to place groups of files within compressed containers known as "archives". It is developed by Igor Pavlov and was first released in 1999. 7-Zip has its own archive format called 7z introduced in 2001, but can read and write several others.

thumb|ReactOS 0.4.14 running the Firefox [[web browser]] ReactOS is a free and open-source operating system for i586/amd64 personal computers that is intended to be binary-compatible with computer programs and device drivers developed for Windows Server 2003 and later versions of Microsoft Windows. ReactOS has been noted as a potential open-source drop-in replacement for Windows and has been of interest for its information on undocumented Windows APIs.

free/libre/open source operating system inspired by BeOS and compatible with its version 5

free software package management system

alt=calculate fractions without common denominator|thumb|Figure 1. Xcas calculates fractions without common denominator. thumb|Figure 2. Xcas can solve equations, calculate derivatives, antiderivatives and more. thumb|Figure 3. Xcas can solve differential equations. Xcas is a user interface to Giac, which is an open source computer algebra system (CAS) for Windows, macOS and Linux among many other platforms. Xcas is written in C++. Giac can be used directly inside software written in C++.

free and open-source office suite

Scribus () is free and open-source desktop publishing (DTP) software available for most desktop operating systems. It is designed for layout, typesetting, and preparation of files for professional-quality image-setting equipment. Scribus can also create animated and interactive PDF presentations and forms. Example uses include writing newspapers, brochures, newsletters, posters, and books.

free and open-source cross-platform game engine for making 2D and 3D games

FileZilla is a free and open-source, cross-platform FTP application, consisting of FileZilla Client and FileZilla Server. Clients are available for Windows, Linux, and macOS. Both server and client support FTP and FTPS (FTP over SSL/TLS), while the client can in addition connect to SFTP servers. FileZilla's source code is hosted on SourceForge.

open source, turn-based strategy game with a high fantasy theme

cross-platform free and open-source music player

AbiWord () is a free and open-source word processor. It is written in C++ and since version 3 it is based on GTK+ 3. The name "AbiWord" is derived from the root of the Spanish word "abierto", meaning "open".

Wireshark is free and open-source packet analyzer software. It is used for computer network analysis and troubleshooting, software and communications protocol development, and education. Originally named Ethereal, the project was renamed Wireshark in May 2006 due to trademark issues.

Cygwin ( ) is a free and open-source Unix-like environment and command-line interface (CLI) for Microsoft Windows. The project also provides a software repository containing open-source packages. Cygwin allows source code for Unix-like operating systems to be compiled and run on Windows. Cygwin provides native integration of Windows-based applications.

free HTML layout engine

free software planetarium

Oracle VirtualBox (formerly Sun VirtualBox, Sun xVM VirtualBox and InnoTek VirtualBox) is a hosted hypervisor for x86 and ARM virtualization developed by Oracle Corporation. VirtualBox was originally created by InnoTek Systemberatung GmbH, which was acquired by Sun Microsystems in 2008, which was in turn acquired by Oracle in 2010.

Krita ( ) is a free and open-source raster graphics editor designed primarily for digital art and 2D animation. Originally created for Linux, the software also runs on Windows, macOS, Haiku, Android, and ChromeOS, and features an OpenGL-accelerated canvas, colour management support, an advanced brush engine, non-destructive layers and masks, group-based layer management, vector artwork support, and switchable customisation profiles.

SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netscape 7.

WebKit is a browser engine primarily used in Apple's Safari web browser, as well as all web browsers on iOS and iPadOS. WebKit is also used by the PlayStation consoles starting with the PS3, the Tizen mobile operating systems, the Amazon Kindle e-book reader, Nintendo consoles starting with the 3DS Internet Browser, GNOME Web, and the discontinued BlackBerry Browser.

TensorFlow is a software library for machine learning and artificial intelligence. It can be used across a range of tasks, but is used mainly for training and inference of neural networks. It is one of the most popular deep learning frameworks, alongside others such as PyTorch. It is free and open-source software released under the Apache License 2.0.

eMule is a free peer-to-peer file sharing application for Microsoft Windows. Started in May 2002 as an alternative to eDonkey2000, eMule connects to both the eDonkey network and the Kad network. The distinguishing features of eMule are the direct exchange of sources between client nodes, recovery of corrupted downloads, and the use of a credit system to reward frequent uploaders. eMule transmits data in zlib-compressed form to save bandwidth.

free software to make screencasts and/or live streaming

thumb|right|Interior of 3D house thumb|right|Arduino board imported from Eagle PCB software

K3b (from KDE Burn Baby Burn) is a CD, DVD and Blu-ray authoring application by KDE for Unix-like computer operating systems. It provides a graphical user interface to perform most CD/DVD burning tasks like creating an Audio CD from a set of audio files or copying a CD/DVD, as well as more advanced tasks such as burning eMoviX CD/DVDs. It can also perform direct disc-to-disc copies.

thumb|Fluxbox 1.3 Xsession running on Debian [[GNU/Linux 7]]

KOffice was a free and open source office and graphics suite developed by KDE for Unix-like and Windows systems. KOffice contains a word processor (KWord), a spreadsheet (KSpread), a presentation program (KPresenter), and a number of other components that varied over the course of its development.

discontinued Ubuntu Linux installer for Windows

open source chess engine

DOSBox is a free and open-source MS-DOS emulator. It supports running programs primarily video games that are otherwise inaccessible since hardware for running a compatible disk operating system (DOS) is obsolete and generally unavailable today. It was first released in 2002, when DOS technology was becoming obsolete. Its adoption for running DOS games is relatively widespread, partly because of its use in commercial re-releases of games.

free software media player

Text editor

OpenTTD is a business simulation game in which players try to earn money by transporting passengers, minerals and goods via road, rail, water and air. It is an open-source remake and expansion of the 1995 Chris Sawyer video game Transport Tycoon Deluxe.

FlightGear Flight Simulator (often shortened to FlightGear or FGFS) is a free, open source multi-platform flight simulator developed by the project since 1997.

LyX (styled as ''''''; pronounced ) is an open source, graphical user interface document processor based on the LaTeX typesetting system. Unlike most word processors, which follow the WYSIWYG ("what you see is what you get") paradigm, LyX has a WYSIWYM ("what you see is what you mean") approach, where what shows up on the screen roughly depicts the semantic structure of the page and is only an approximation of the document produced by TeX.

LilyPond is a computer program and file format for music engraving. One of LilyPond's major goals is to produce scores that are engraved with traditional layout rules, reflecting the era when scores were engraved by hand.

KHTML is a discontinued browser engine that was developed by the KDE project. It originated as the engine of the Konqueror browser in the late 1990s, but active development ceased in 2016. It was officially discontinued in 2023.

MuseScore Studio (branded as MuseScore before 2024) is a free and open-source music notation program for Windows, macOS, and Linux under the Muse Group, which owns the associated online score-sharing platform MuseScore.com and a freemium mobile score viewer and playback app.

software application

discontinued Internet suite

Code::Blocks is a free, open-source, cross-platform IDE that supports multiple compilers including GCC, Clang and Visual C++. It is developed in C++ using wxWidgets as the GUI toolkit. Using a plugin architecture, its capabilities and features are defined by the provided plugins. Currently, Code::Blocks is oriented towards C, C++, and Fortran. It has a custom build system and optional Make support.

Media player for Microsoft Windows

qBittorrent is a cross-platform free and open-source BitTorrent client written in native C++. It relies on Boost, OpenSSL, zlib, Qt 6 toolkit and the libtorrent-rasterbar library for the torrent back-end, with an optional search engine written in Python.

AutoHotkey (AHK) is a free and open-source custom scripting language for Microsoft Windows, primarily designed to provide easy keyboard shortcuts (or 'hotkeys'), fast macro-creation, and software automation, to allow users of most computer skill levels to automate repetitive tasks in any Windows application. It can easily extend or modify user interfaces (for example, overriding the default Windows control key commands with their Emacs equivalents).

Script Creation Utility for Maniac Mansion Virtual Machine (ScummVM) is a set of game engine recreations. Originally designed to play LucasArts adventure games that use the SCUMM system, it also supports a variety of non-SCUMM games by companies like Revolution Software and Adventure Soft. It was originally written by Ludvig Strigeus. ScummVM is free software that is released under the terms of the GNU General Public License.