Debian in the context of "Linux"

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. Firefox is available for Windows 10 or later versions of Windows, macOS, and Linux. Its unofficial ports are available for various Unix and Unix-like operating systems, including FreeBSD, OpenBSD, NetBSD, and other operating systems, such as ReactOS. It is the default, pre-installed browser on Debian, Ubuntu, and other Linux distros. Firefox is also available for Android and iOS. However, as with all other iOS web browsers, the iOS version uses the WebKit layout engine instead of Gecko due to platform requirements. An optimized version was also available on the Amazon Fire TV as one of the two main browsers available with Amazon's Silk Browser, until April 30, 2021, when Firefox would be discontinued on that platform. Firefox is the spiritual successor of Netscape Navigator, as the Mozilla community was created by Netscape in 1998, before its acquisition by AOL. Firefox was created in 2002 under the codename "Phoenix" by members of the Mozilla community who desired a standalone browser rather than the Mozilla Application Suite bundle. During its beta phase, it proved to be popular with its testers and was praised for its speed, security, and add-ons compared to Microsoft's then-dominant Internet Explorer 6. It was released on November 9, 2004, and challenged Internet Explorer's dominance with 60 million downloads within nine months. In November 2017, Firefox began incorporating new technology under the code name "Quantum" to promote parallelism and a more intuitive user interface.

Firefox usage share grew to a peak of 32.21% in November 2009, with Firefox 3.5 overtaking Internet Explorer 7, although not all versions of Internet Explorer as a whole; its usage then declined in competition with Google Chrome. As of February 2025, according to StatCounter, it had a 6.36% usage share on traditional PCs (i.e. as a desktop browser), making it the fourth-most popular PC web browser after Google Chrome (65%), Microsoft Edge (14%), and Safari (8.65%).

Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative, public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software.

Open-source software development can bring in diverse perspectives beyond those of a single company. A 2024 estimate of the value of open-source software to firms is $8.8 trillion, as firms would need to spend 3.5 times the amount they currently do without the use of open source software.

Ubuntu (/ʊˈbʊntuː/ uu-BUUN-too) is a Linux distribution based on Debian and composed primarily of free and open-source software. Developed by the British company Canonical and a community of contributors under a meritocratic governance model, Ubuntu is released in multiple official editions: Desktop, Server, and Core for IoT and robotic devices.

Ubuntu is published on a six-month release cycle, with long-term support (LTS) versions issued every two years. Canonical provides security updates and support until each release reaches its designated end-of-life (EOL), with optional extended support available through the Ubuntu Pro and Expanded Security Maintenance (ESM) services.

SteamOS is a gaming-focused operating system released by Valve that incorporates the company's video game storefront, Steam. Based on Arch Linux and built specifically to support Steam, it is the default Linux distribution for Valve's line of gaming hardware, including the Steam Deck, Steam Machine, and Steam Frame. Beginning in 2025, Valve expanded official support to include third-party devices designated as "SteamOS Compatible", such as handhelds like the Lenovo Legion Go and Asus ROG Ally. It can also be installed on personal computers without official support from Valve. The core operating system is free and open-source software, while the Steam client remains proprietary.

SteamOS was first released in 2013, with versions 1.0 and 2.0 based on Debian and designed primarily as a client for streaming games over a local network from a gaming PC, with limited support for native gameplay. Valve promoted the platform as part of a broader effort to expand Linux gaming. In 2022, Valve introduced SteamOS 3.0 alongside the launch of the Steam Deck. This version transitioned to an Arch Linux base which used a rolling release model that Valve felt was better suited for hardware support. It has a dual‑mode interface: a console‑style mode powered by Steam's Big Picture UI, and a KDE Plasma desktop environment for traditional computing use. SteamOS 3.0 also incorporates Valve’s Proton compatibility layer, enabling many Windows games to run on Linux.