open-source software
software that anyone is free to use and redistribute in its current state with a permissive licence giving a libre access to its original source code (but no necessarily to modify it)
Marlin
open source firmware for 3D printers
Eclipse Theia
free and open-source IDE framework for desktop and web applications
Synchronizer
Tool for keeping Lua modules, templates and other pages synchronized across Wikimedia wikis
free software
software distributed under terms that allow users to freely run, study, change and distribute it and modified versions
Apache Subversion
advanced version control system
Apache Directory
open source project
Sinatra
software
Visualization Toolkit
free software system for 3D computer graphics, image processing and visualization
Leaflet
JavaScript library for web interactive cartography
Blacklight
open source Ruby on Rails Engine for creating search interfaces on top of Apache Solr indices
Computer Vision Annotation Tool
free and open source, web-based image and video annotation tool
Beyond All Reason
open source real time strategy game
Orbiter
2000 video game
Horde
open-source web-mail
Impulse Tracker
audio tracker for DOS
Chaos engineering
In software engineering, experimenting with the product to test extreme situations.
Google Lighthouse
open-source, automated tool for measuring the quality of web pages
Facebook Container
privacy add-on for Mozilla Firefox
Python
general-purpose programming language
Audacity
open-source digital audio editor and recording application
Berkeley Open Infrastructure for Network Computing
open source middleware system for volunteer and grid computing
Erlang
programming language
open-source video game
video game whose source code is open-source software
Einstein@Home
BOINC volunteer computing project that analyzes data from LIGO to detect gravitational waves
Open Dental
Dental practice management software
Fiji
open source image processing software
Lean
software for interactive and automated theorem proving
Electron
framework that enables cross-platform desktop applications
.NET
free and open source cross-platform software platform developed by Microsoft
Synapse
collaborative research platform