In the context of this page, Linux is a family of operating systems that is based around the Linux kernel. A Linux distribution (or "distro") is the kernel packaged up with various applications and programs to create a fully functional operating system that can be installed on a computer. If you think of an operating system as a vehicle, the Linux kernel is the engine. A single engine design can can support multiple types of vehicles, with each vehicle catering to certain customers' specific needs.
Given this flexibility in how one can build an operating system around the Linux kernel, this gave rise to many philosophies in how to create said operating system. For instance, some may aim for maximum performance, while others aim for stability.
Wikipedia has an image
showing a timeline of many Linux distributions and their lineage if they were branched off one from another distribution. There's also a comparison of selected distributions
.
The Main Distributions
While there are dozens upon dozens of distributions, most of them have branched off from one of these main roots. Slackware
One of the first distributions to be widely circulated. Its goals are to be the most "Unix-like" distribution with as few software packages and modifications as possible. As such, it requires more work to get it set up and is recommended for advanced Linux users. Some notable distros based on Slackware include Slackel, Salix and Zenwalk Linux. SUSE
A project that originally started from a company providing software packages for early Linux distributions such as SLS and Slackware, they eventually began rolling out their own distribution using Slackware as the basis. However, after a couple of years they switched to using Jurix as the basis for the distribution, before morphing it into its own thing. The distribution settled down into two main versions: SUSE Linux Enterprise aimed at supporting commercial operations with the aim of providing stability and reliability, and openSUSE (which also spawned a user-friendly distribution in GeckoLinux, as well), the community supported version that offers bleeding edge features. Debian
Debian's aim is to be as stable as possible, boasting smooth upgrades between major and minor versions. With stability also comes security, two things the Debian maintainers boast. Because of this, Debian has many distributions based on it, with Ubuntu and its children being one of the most successful line of derivatives. The main drawback to using Debian is that it's slow to integrate features and such. So if you want to be on the bleeding edge of Linux operating systems, Debian is not a good choice for that. Though that doesn't preclude its offshoots being more on the cutting edge of user facing operating system features.Other notable distributions based on Debian include Devuan (an all-purpose distribution using init systems such as OpenRC, runit and sysvinit), MEPIS OS spinoffs MX Linux (midweight distribution using sysvinit) and antiX (a truly systemd-free distribution that can run OpenRC, runit, s6 and s6-66 along with sysvinit), elementary OS (for newcomers from Apple Mac OS), Zorin OS (for newcomers from Windows), deepin, Linux Mint, Pop!_OS and early versions of both Solus and steamOS.
Red Hat
A distribution aimed at the commercial and enterprise market, Red Hat takes advantage of a note in GNU's philosophy that even though software down to its source should be made freely available, that doesn't mean one can't find a way to make money off of it. The company that originally maintained it was even bought out by IBM. As such, Red Hat doesn't sell a product (the software), it sells a service (support).However, due to the package management services requiring a subscription fee, Red Hat has spawned free (as in beer, also known as gratis) community supported offshoots in Fedora, with some like AlmaLinux, EuroLinux and Rocky Linux used by smaller businesses in place of Red Hat. Some notable Fedora forks include Nobara (primarily for gamers and streaming, as risiOS merged with it as of January 2024) and Ultramarine (the spiritual successor to the all-purpose fork Korora).
A notable past fork based off of the former Red Hat Linux called Yellow Dog Linux, which got its fame for being Sony's OS of choice to run on the PlayStation 2 and likely the intended OS for the PlayStation 3's "Other OS" feature. It also gave the namesake of Red Hat's "yum" (Yellowdog Updater Modified) package management system.
Gentoo
Gentoo, previously named Enoch, is all about performance and customizability. To this end, virtually everything on a Gentoo system is built from source code. The Portage package manager lets the user specify the features they want and don't want in each app through USE flags, so apps can be built specifically for their intended use case without unnecessary functionality. Such customization is not possible with conventional Linux distributions that provide ready-made executables. This build process also allows the use of machine-specific compiler optimizations to maximize performance for the specific hardware in use. But these advantages come at a cost. Gentoo is notorious for being one of the most difficult Linux distributions to properly install and configure, and the compilation process can be extremely taxing on hardware. Some apps, such as Chromium,note can require hours to compile, even on the fastest consumer multi-core processors. For these reasons, compiled binary packages are also available.Its most popular offshoot is Chrome OS. Other distributions from it include Funtoo, Calculate Linux, Mocaccino OS (formerly Sabayon), Pentoo and Redcore Linux.
Arch
Arch's primary philosophy is to be on the cutting edge. As such, it uses a rolling release model for updates; going so far as to release monthly snapshots as installation media. Applications are distributed as compiled binaries. Arch is officially only optimized for x86-64 architectures, although there is also limited community-backed support for ARM and the legacy x86 architecture. In addition, Arch also holds onto the design philosophy that things are kept as simple as possible, such as having no official graphical front-end for its package distribution system (although a third party GUI front-end, tkpacman, does exist), or even a desktop GUI at all by default. And initially there was zero hand-holding when it comes to preparing the machine for installation by default—the user is expected to understand and know how to partition the storage device prior to installation. This caused it to be known as one of the harder distributions to work with. However, Arch provides the archinstall guided installer with the installation medium since 2023. This eases installation tremendously as despite being still text-based, it sets up a preliminary and usable system after asking the user a few questions.Notable distributions based on Arch include Endeavour OS (based off of Antergos, a former all-purpose installer distribution), Manjaro, Garuda (mainly centered around gamers or power users), ArcoLinux, Artix Linux (a distro that uses different init systems such as OpenRC, runit, dinit and s6-66), Obarun (a distribution that only uses the s6-66 init system) and recent versions of steamOS.
Other notable operating systems based on the Linux kernel
These operating systems used the Linux kernel and are notable in either a historic way, built around a gimmick, or for some other unique attribute, but were not based on one of the main distributions described previously. Softlanding Linux System (SLS)
SLS was one of the very first distributions to hit the scene. The name "softlanding" comes from the idea that it has a "gentler" learning curve for DOS users to transition to. However, a lot of its users found SLS to be buggy, to the point where some of them decided to do one better. This spawned Slackware, which started off as a clean-up project of SLS, and Debian. Linux From Scratch
More of an e-book than a Linux distribution , the e-book contains instructions to build a working Linux distribution from scratch. It is very time-consuming and somewhat difficult as it assumes that the user has a basic understanding of how Linux works, and new users are advised to steer clear of it; as even straying from the formula a bit would result in failure. Likewise, it is often recommended to newbies by trolls to create frustration.As a side note, Linux From Scratch is only the first book from a series of two and ends with your build having only a basic text only system with minimal networking support. You're then expected to move on to the second book of the series, Beyond Linux From Scratch, which will guide you towards building the more advanced components that make up a desktop environment and making the system more user friendly.
DD-WRT
A Linux distribution that aims to be the replacement firmware for a number of routers, most notably Cisco's and Linksys' kits. You're likely to have heard of it while browsing for router suggestions online. This distribution has three spinoffs: OpenWRT, AdvancedTomato (formerly TomatoWRT) which is a fork of DD-WRT that specializes on Broadcom System-on-Chips, and AsusWRT-Merlin (formerly MerlinWRT) which primarily targets Asus routers. Puppy Linux
A lightweight Linux distribution that really puts the emphasis on lightweight. Whereas most other lightweight distributions tend to be a minimal build of say Debian with a lightweight desktop environment, Puppy Linux is its own thing, being capable of running on hardware from around the late 90s to early 2000s. It may have spawned even lightweight distributions like Damn Small Linux (which was at most 50MB) and Tiny Core Linux (which builds off the work from Damn Small Linux).Android
A Linux-based OS designed for mobile devices, although it was later co-opted by set-top boxes and Smart TVs. Although it had a slow start in the late 2000s, its open nature allowed many manufacturers to build a smartphone based around it. It eventually displaced other smartphone based OSes like Blackberry OS, webOS (from Palm), Symbian OS (latterly from Nokia), and Windows Mobile. It's now the most popular smartphone OS, outpacing its immediate competitor of Apple's iOSnote nearly 3 to 1.As for offshoots, mobile manufacturers often distribute Android with their own customisations (such as TouchWiz and OneUI from Samsung) but these are usually still authorized to call themselves Android and use the Google Play app store; exceptions include Amazon's Fire OS and certain versions of Huawei's EMUI which use their own app stores. Android has also been spun off several times, the most active spinoff at the moment is LineageOS. Android was primarily made with ARM processors in mind, but there is a fork named Android-x86 that is Exactly What It Says on the Tin, an Android system geared for x86_64 processors made by Intel and AMD with its own slew of spinoffs such as Bliss OS, Remix OS and Phoenix OS. And yes Windows recently added support for Android apps with Windows 11.
As Many modern Linux users got their start with Android, so in a way, Android is considered a Gateway Series.
kaiOS
What Android is to smartphones, kaiOS is to keypad based, lower end feature phones. It had its roots from the defunct smartphone OS alternative Firefox OS, reworked to be light on resource usage, updated for the latest web technologies with help from Mozilla, and apps are primarily web-based despite having an app store.Red Star OS
Red Star OS note is a North Korean Linux distribution, with development first starting in 1998 at the Korea Computer Center (KCC). While earlier versions have designs modelled after Windows XP or 7, version 3 onwards are made to look like Mac OS. We strongly advise against trying to obtain the OS and trying it out as the OS ostensibly contains a number of features that allows the North Korean Government to spy on you. Raspberry Pi OS
Previously known as Raspian, as it was originally forked from Debian. This is a customised distribution intended for use with the Raspberry Pi family of compact single-board computers, and optimised to run on their hardware. As a seriously popular choice for hobbyists (it's the best selling British computer in history, surpassing the unit sales of the previous record holder, the ZX Spectrum, as of 2015) the Pi and Pi OS have become a pretty popular way to begin using Linux.Asahi Linux
Shortly after Apple released their new M1 based computers, Linus Torvalds expressed interest in porting Linux to the new platform. However, he didn't want to take on the project himself, leading to Hector Martin to start on the project. Martin's cred includes hacking the Wii to allow for homebrew, as well as the PlayStation 3 and 4, the latter of which he installed on Linux on and ran Steam. While a build of the OS can run on Apple silicon Macs, as of 2024, the software is considered in its alpha stages.Which distribution to start with?
The first question most people ask when getting into Linux for the first time is which distribution should they go with? Typically one designed for user-friendliness such as Ubuntu or Linux Mint are highly recommended as they hide much of the more nuanced things you have to learn with the other types of Linux distributions. Some even aim to emulate Windows or macOS to ease the learning curve in using another OS. Overall though, unless you're doing something really esoteric or novel, there's likely a Linux distribution that suits your needs.