This feature first appeared in the Summer 2015 issue of Certification Magazine. Click here to get your own print or digital copy.

Linux distributions, or "distros" as they're popularly known, are unique to the Linux environment. You don't hear of Windows or Mac distributions. What is it about Linux that makes distributions necessary? Once you know what Linux is, then you realize why distributions are an essential aspect of Linux.

What is a Linux distribution?

Linux is open source software; it isn't developed by a single entity, unlike Windows (which is developed by Microsoft), and is a complete operating system. What we commonly call "Linux" is a kernel, or the core, of a Linux operating system — it is not an operating system in itself. If you want your device to run on Linux, you'll need to install a Linux distribution, which is essentially a Linux operating system.

A Linux distro consists of the kernel, terminal interface and terminal commands, graphical programs and system management services. While it's possible to get the source code of the kernel and the other programs and compile the software to build an operating system, it requires expertise and time. That's why most users prefer installing a distro.

Installing one of the many Linux distributions available not only saves time — to say nothing of quite a lot of hard work — but it also makes subsequent software and security updates (as well as new software installations) quick and easy, because these are available in packages.

What does it take to create a new distribution?

Though most Linux users prefer to install the distro that suits them best, a few opt to compile their distributions from scratch, or modify an existing distro.

If you want to build from source, then you need some experience with Linux, including command-line skills, an existing Linux system on which to work, and the Linux kernel source code, as well as the source codes of any system utilities — including at least one graphical desktop — and packages you want to include.

For users keen on building their own distros, the Linux from Scratch (LFS) project is a good place to start.

Why are there so many Linux distributions?

The list of existing Linux distros is long, running to 600 and more, making newcomers to Linux wonder why there are so many. Some experienced users reckon that the sheer number of distros tends to confuse beginners — particularly those accustomed to working on Windows — and may deter many from using Linux, thereby limiting its reach.

That there are so many Linux distros isn't surprising considering users have many different needs. Since Linux is open source, distributions have been created to cater to a wide range of possible uses. There's no one-size-fits-all Linux distribution; different distros suit different purposes. Some are suitable for desktops, some for servers, and others for multimedia devices.

Users have the freedom to choose a distro based on what one intends using it for, as well as one's level of expertise. Those who prefer a simple desktop operating system might like Ubuntu or Mint. Those who work in a server environment would likely prefer a more stable distribution such as Debian or Red Hat Enterprise Linux (RHEL).

Linux offers users the choice of either installing a distribution that most closely fits their needs, building a new one one from scratch, or taking an existing distribution and tweaking it until it is fit for their purposes. No wonder, then, that there are so many distributions.

Widely-used distributions

Though there are hundreds of existing Linux distros, only a few are well known. Users tend to look for distributions that are easy to install, are cost-effective, are backed by easily accessible commercial support and are stable. Advanced users usually prefer distributions that they can configure and control.

Ubuntu — This Debian-based distro is one of the most popular Linux distributions for desktop as well as server environments. For newcomers, as well as experienced users, Ubuntu is the distro of choice for a number of reasons that include an easy installation process, top-notch commercial support and six-month releases. Every 2 years, Ubuntu releases its Long Term Support (LTS) version, the server edition of which is supported for 5 years.

OpenSUSE — This may not be the most user-friendly desktop distro for newcomers because it isn't as simple to install as Ubuntu. Also, its system-management tool, YAST (Yet Another Setup Tool), which is designed to handle everything from system configuration to administration to software installation, can appear quite complicated to inexperienced users. Skilled users, though, like YAST because it gives them a high degree of control. OpenSUSE issues releases every eight months. OpenSUSE is perhaps most popular as an enterprise desktop distribution.

Linux Mint — Based on Ubuntu, Linux Mint is one of the most widely-used desktop distributions today, partly because it's easy to install and use and, unlike Ubuntu's Unity, Mint's default desktop is traditional and more accessible to relatively unskilled users. Users can choose between Mate and Cinnamon, Linux Mint's two Genome-based interfaces, of which Cinnamon is more compact and easier to navigate. It also has an efficient Software Manager and preloaded audio and video packages.

Linux Mint is suitable for desktop users looking for a neat out-of-the box distribution.

Fedora — Fedora was built as an alternative to Ubuntu, but it isn't as user-friendly and tends to be more suitable for advanced users. Its Genome 3 desktop is not for the unskilled user � a certain level of skill and familiarity with Linux is required to find one's way around the interface. Fedora has other drawbacks as well: It isn't easy to install, and it lacks multimedia software and a serviceable application manager. With its server-based features, Fedora suits skilled users working in an enterprise environment.

Mageia — Mageia is derived from Mandriva Linux, which was designed to be user-friendly. A community-developed fork of Mandriva Linux, Mageia is backed by solid support from Mageia.org, the community organization. Mageia releases updates approximately every 9 months, which are supported for 18 months.

Mageia comes with both KDE and Genome desktops, as well as plenty of software. It's also easy to install and offers advanced users more options during the installation process. Experienced users like the Mageia Control Centre, which enables them to control most aspects of the operating system. This is a functional and well-supported Linux distribution that is suitable for both routine as well as advanced computing.

Debian — Debian, which is compiled out of only open-source software, has been around for more than 20 years and is still the distribution of choice for those looking for a stable server operating system. It is a flexible, well-tested system that can be configured for different environments. Because it's exhaustively tested, it is a very secure distribution.

It doesn't come with proprietary software, but packaged software for Debian is available from a host of software vendors. Unlike other distributions, Debian doesn't come with formal commercial support. That isn't a drawback, however, because community support is available from Debian consultants the world over, whom users can connect with through the Consultants page.

Gentoo — Gentoo is for skilled users who're willing to spend hours or even days on the installation alone. It's not a ready-to-use system, but one that requires the user to participate in the building process, enabling him to configure it according to his needs. The user needs to do most of the compiling from source, so one needs to either know Linux, or be willing to spend much time learning on the job. Gentoo might suit users looking for a powerful system that they can control.

Unlike other distributions, Gentoo doesn't issue releases cyclically, but delivers upgrades and packages through system updates. All users need to do is install system updates in order to ensure that their system has all the latest packages and software upgrades.

Arch Linux — Like Gentoo, Arch Linux is another Linux distro that requires the user to configure the system according to what he wants to do with it. Unlike newer, more feature-rich distros, Arch Linux is a minimalist and flexible operating system that doesn't take up a lot of space. Users are given the freedom to tweak the system as suits them and install software of their choice. Instead of installing the distro via a graphical interface, users are provided with configuration files that they can edit to configure a suitable server operating system.

Arch Linux rolls out upgrades and new software with its system updates, so updating one's system regularly ensures that all Arch Linux system files and applications are current. Arch Linux and Gentoo are both intended for skilled users, or for those who are willing to learn Linux. Arch Linux is more popular, however, because it ships with binaries, thereby saving users the time needed to compile software from source. Arch Linux is much quicker to install than Gentoo.

Red Hat Enterprise Linux — Red Hat Enterprise Linux (RHEL) is a proprietary distribution that's widely used in the enterprise sector as a server and workstation operating system. Enterprise users prefer RHEL, which is based on Fedora, because Red Hat's excellent long-term commercial support makes it a more stable system. RHEL is patented and can't be redistributed, but CentOS is its free open-source version. RHEL suits skilled enterprise users looking for a secure, stable and compact system that they can control.

Slackware Linux — First released in 1993, Slackware is one of the oldest existing Linux distributions. It's still widely used by advanced users as a server operating system. Like Arch Linux, Slackware puts the user in charge, letting him install system files and packages of his choice. Configuration is mostly command-based, so the user needs to be fairly well-versed with Linux.

Your imagination is the limit

For users willing to engage their senses at a higher level than the "click to install" paradigm familiar to most, Linux offers a robust (and inexpensive) alternative to more traditional operating systems. Linux is matchless for the choice and flexibility it offers. The higher one's level of expertise, the more freedom one has to configure a perfectly tailored, optimal operating system.