An insider's look at the top distros, revealing both their strengths and their weaknesses.
GNU/Linux offers a bewildering variety of flavors -- or distributions, as they're called. To a newcomer's eye, many of these seem virtually identical to each other.
Yet, the more you learn about a distribution and the community that surrounds it, the more different they become. Here, in alphabetical order, is a list of the seven distributions that have most affected GNU/Linux as a whole:
Named for founder Ian Murdock and his wife Debra, Debian may be the most influential GNU/Linux distribution yet. From Ubuntu, Knoppix, and MEPIS through to Xandros and Linspire, many of the best-known distributions today are based on Debian, and the percentage holds roughly true in any listing of distributions. Moreover, with over 1,000 developers and some 20,000 packages, as well as support for 11 different hardware architectures, Debian has a strong claim to being one of the largest free software projects in existence.
Debian is distinguished by its repository system. Each new package enters the unstable repository, then passes through testing to stable status as it meets quality assurance standards. Each of these repositories is further subdivided into three sections: Main,which contains only free software; contrib, which contains free software that requires non-free software to use, and non-free, which contains software not released under a free license. This system allows users to choose the high dependability of official releases, or to choose the balance between cutting edge software and dependability that they prefer. Similarly, the subdivisions allow users to choose the level of software freedom on their systems.
Debian has a reputation for being hard to install and use, neither of which is true today. The new Debian installer released a couple of years ago has taken the pain out of installation, while the prevailing ethos today seems to be to accommodate all levels of users from newbie to expert. Similarly, the frequent complaint that official releases are slow to emerge is largely irrelevant, since most users can get the latest software simply by installing from the appropriate repository.
What is true is that much of Debian's business is conducted publicly via mailing lists and votes, and with a minimum of politeness. This free-for-all is constantly luring outsiders to believe that Debian is about to fragment, yet somehow it never does. Still, the bluntness in the community can be intimidating at times.
Fedora and Red Hat Enterprise Linux (RHEL)
One of the oldest and most successful commercial distributions, these days, Red Hat is divided in two, with Fedora the community face and RHEL the corporate face. Although Red Hat is no longer as influential as in the days when its Red Hat Package Manager (RPM) was the norm, the two distributions remain among the most influential.
Fedora's main reputation is for being the first distro to include new innovations. For instance, Fedora was the first distribution to include tools that allowed average users to work with SELinux's detailed security options. In the same way, Fedora 7 was the first to include Smolt, a program for collecting hardware information about users; Revisor, a program for creating custom install disks, and the Liberation typefaces that provide the metrical equivalents of Arial, Helvetica, and Times Roman in free fonts. Although some users on Fedora mailing lists suggest that this innovation makes Fedora unsuitable for servers and mission-critical operations, an increased attention to testing is starting to make that generality obsolete. After a slow couple of years, Fedora is also well on the way to realizing its goal of creating a thriving community in which Red Hat is important, but no longer completely dominates decision-making.
For its part, RHEL remains one of the most successful commercial distributions. Since RHEL is released every 18-24 months, compared to Fedora's six-month schedule, it benefits from patches to Fedora to make a stable release. Much of RHEL's commercial success may be due to the Red Hat Certification Program, which is widely regarded as one of the most rigorous -- and, therefore, most desirable -- in the business.
Next page: top Linux distros, cont.
Gentoo is often said to be not a distribution so much as a philosophy. If so, that philosophy may be that of FreeBSD, from which it originally developed its emphasis on security and optimization. First released in 2002, it quickly gained a reputation as a geek's distro, largely because it required all packages to be compiled for maximum optimization for each system. This process could take days to complete, and could mean many wasted hours if you made a mistake.
Perhaps in response, Gentoo developed one of the comprehensive sets of documentation available in free software. Moreover, Gentoo has evolved over the years. It now features a Live CD and a graphical installer, while retaining a high degree of customization. In addition, probably only Debian supports a greater number of hardware architectures.
Since the departure of Daniel Robbins in 2004 to work at Microsoft, Gentoo seems to have lost direction. Robbins's recent blog suggesting that the governance of the distribution was in such disarray that control of it might as well pass to him, while not altogether serious, serves only to emphasize the lack of organization and direction in the distribution. Yet, while Gentoo itself may have lost much of its prominence, it remains the source of several other distributions, such as Sabayon and Ututo.
Originally known as Mandrake, Mandriva was founded in 1998 and was originally based on Red Hat. Its current name combines elements of Mandrake with Conectiva, a Brazilian distro it acquired in 2005.
Early in its history, Mandriva developed a strong reputation for its emphasis on desktop usability. Its innovations included urpmi, one of the first RPM-based package systems to resolve dependencies, as well as DrakConf (AKA the Mandriva Control Center), one of the most thorough collection of graphical administration tools available for GNU/Linux. Its installation program is reasonably comprehensive while still being user-friendly.
In recent years, Mandriva has struggled to overcome what appears to be an over-expansion, bankruptcy, and a copyright struggle with the Hearst Corporation, which owns the rights to the Mandrake the Magician comic. Even worse, the firing of founder Gael Duval created a controversy in the free software community in 2006. Nor have users warmed to the Mandriva Club, which seems to have degenerated into no more than a way to support the distribution, rather than the nucleus of a community that it was evidently intended as.
Despite these setbacks, Mandriva remains one of the top three commercial distributions, and recent years have seen it starting to recover some of its reputation.
Founded by Patrick Volkerding in 1993, Slackware beats out Debian for the title of the oldest still-active distribution by a matter of weeks. It has a long, well-deserved philosophy as a stone geek's distribution.
This reputation is based on its use of a command-line installer and utilities and an avoidance of anything that could be considered bloated software -- including GNOME and OpenOffice.org. Instead of providing graphical interfaces, Slackware requires direct editing of GNU/Linux's text-based configuration files. And, instead of providing a package system, Slackware continues to rely on compressed tar files, with no mechanism for resolving dependencies.
The trade off for these demands is a fast-running system that rivals or exceeds Debian stable for its reliability. Moreover, much of what a desktop user would see as deficiencies are provided by unofficial projects surrounding software.
Slackware is impressive to see in operation, yet it will never be a popular distribution. However, it remains the basis for countless other distributions, including SLAX, NimbleX, and VectorLinux. Most of these distributions try to add some user-friendliness to Slackware without losing its stability and speed.
Next page: the end of the list; plus some thoughts about the future of distros
SUSE Linux Enterprise / OpenSUSE
Founded in Germany in 1996, today SUSE Linux Enterprise is one of the top two commercial distributions, fighting Red Hat Enterprise Linux for predominance. openSUSE is its community version. Traditionally, SUSE had the reputation of being most popular in Europe, although it also has a large North American following.
If a single feature defines both versions of SUSE, that feature is YaST2, its centralized distribution tool that resembles the KDE Control Center on steroids. In fact, in openSUSE's version of KDE, YaST2 replaces the Control Center. Besides its comprehensive collection of configuration tools, one of the most useful features of YaST is that it is available in both graphical and text-based versions. That means that users who log in to their systems in single-user mode to repair their system can use the same tool set as when they are running the X Window System.
While still prominent, SUSE has fallen under some criticism lately. Many long-time users have never forgiven Novell's purchase of the distribution, nor the change from KDE to GNOME as the default desktop. Such users tend to regard openSUSE as the natural successor to early versions of the distributions.
Even more seriously, Novell's development and distribution deal with Microsoft in November 2006 has resulted in efforts to boycott the distribution. This deal caused two major clauses to be added to the third version of the GNU General Public License, and provoked many calls to punish Novell by making it unable to use the license in some way. Novell also lost prominent employees such as Jeremy Allison, leader of the Samba project, because of the deal. This hostility may also have hampered the growth of openSUSE into a strong community.
However, what the long-term effect will be on either SUSE Linux Enterprise or openSUSE is still unknown. It may be that, with Novell's strong support and certification programs, that the company will manage to weather the controversy, especially if it makes some effort at reconciliation with the free software community.
Based on Debian, Ubuntu has confounded those who believed there was no longer room for a major new distro by becoming the most widely known and used distro in less than four years.
This rapid growth is due in large part to the energy and investment of Mark Shuttleworth, the South African multi-millionaire who was also one of the first space tourists. Self-appointed dictator of Ubuntu, Shuttleworth also heads Canonical, the commercial arm of Ubuntu.
However, credit must also go to Ubuntu's success in learning from the real and perceived problems of Debian. Not only is the basic Ubuntu desktop more organized than Debian's, but the Ubuntu community, with its code of conduct to enforce civility, is generally a much less intimidating place than Debian's -- so much so that Debian has suffered a number of defections of prominent developers to Ubuntu. In addition, Ubuntu's six month release cycle is much shorter than the periods between official Debian releases.
Another notable feature of Ubuntu is its encouragement of sub-communities. Although the basic Ubuntu distribution uses the GNOME desktop, Kubuntu uses the KDE desktop, and Xubuntu the Xfce desktop. Other variations are Edubuntu, which features educational tools, and the upcoming Gobuntu, which uses only free software.
Until recently, Ubuntu has faced little criticism. However, in the last year, some free software users have complained about the use of non-free drivers in one or two releases, while others have voiced concerns about the increasing move towards commercialization of the distribution. As well, after a promising start, Ubuntu's rate of innovation seems to be slowing in recent releases. Yet, overall, Ubuntu remains a widely used distribution. In the last year, it has even become the source of its own spinoff distributions, including Linspire, and, for one release, MEPIS.
This list could easily continue, with mention of such distros as Damn Small Linux, Frugalware, K12LTSP, Knoppix, and others. Each of these distributions has its own claim for being influential, but, beyond the seven detailed, agreement about which ones ought to be included would be less unanimous.
However, if you wanted a summary of GNU/Linux's to this point, then the development of these seven distributions would be a better starting point than most. Only some of the earliest history concerning such extinct distros such as Yggdrasil, would be missing.
As for the future -- who can say? Already, several of these seven are important less for themselves than for the traditions they have started. And, just in case anyone starts thinking that the selection of distributions is becoming settled, remember that nobody predicted the rise of Ubuntu. Admittedly, Ubuntu had several advantages from the start, but, given the unpredictability of free software, perhaps a new distribution with an influential new philosophy and toolbox is being readied as you read.