Fedora and Red Hat Enterprise Linux (RHEL) are the most influential distributions that use the Red Hat Package Manager. Although their influence lags behind that of Debian and Ubuntu, it is still strong enough that Fedora remains consistently in the top three most downloaded distributions on Distrowatch, and is the ultimate source of 50 (15%) of the 323 active distributions listed.
Fedora, the successor to Red Hat Linux and perhaps the most influential distribution prior to 2000, is consciously produced as the source for other distributions. In many of its releases, it is among the most innovative distros, releasing new software developed in co-operation with upstream projects. Development is more or less continuous within its Rawhide repository, with stable releases produced every six months.
However, RHEL is only the start of Fedora's influence. Just as Ubuntu has supported the development of sub-projects like Kubuntu and Xubuntu, so Fedora has encouraged spins and remixes -- customized releases of Fedora designed for specialized purposes.
Moreover, directly and through RHEL, Fedora has inspired a variety of independent distributions. All-purpose distros, ones for live CDs, or for localizations, specific hardware or security and servers -- the Fedora derivatives include them all, creating an ecosystem of choices that sometimes resembles those available for Debian or Ubuntu, but also shows its own specializations.
Fedora Spins and Remixes
Fedora uses the word "spin" for any result that contains only software from Fedora repositories, and "remix" for any result that contains software from other sources, distinguishing between the two by differences in trademarks. In addition, spins are registered and carried on many Fedora mirror sites as an official parts of Fedora.
The exact number of Fedora spin and remixes is hard to determine. With Fedora's Revisor tool, users can produce their own spins and remixes from the desktop. As a result, many spins and even more remixes are probably never registered. In fact, the ease of creating spins and remixes may explain why Fedora has fewer derivative distros than Debian -- for many purposes, producing a spin or remix is far easier than maintaining a distro.
Some of Fedora's spins provide a different desktop. Of these, the most popular is the KDE spin, since Fedora itself defaults to GNOME. In fact, the KDE spin is consistently the most popular one. However, those for Xfce and LXDE and Sugar on a Stick are among the most-often downloaded spins as well.
The line between derivatives and spins and remixes is especially thin among the all-purpose derivatives. For instance, aside from language, the point of Open Xange, a month-old Portuguese derivative, is largely that it uses KDE rather than GNOME. Similarly, Kororaa, which was originally a Gentoo derivative, is now dependent on Fedora. Kororaa's home page even goes so far as to describe the distro as a Fedora remix. Fusion would also count as a remix, since it contains non-free software that Fedora does not carry in its repositories.
A more ambitious general derivative is CentOS. Based largely on RHEL source code, CentOS is a community-based distribution for enterprise installations. Although lacking the resources that are behind RHEL and sometimes being slow to release, CentOS is probably the most-respected Fedora derivative. Given that CentOS provides still another level of testing and refinement, this reputation is understandable.
In its own way, Blag is no less ambitious. However, its goal is to make a distribution that only contains free software. Its name an acronym for Brixton Linux Action Group, the distribution reveals a fondness for activist rhetoric on its web site, and is one of a handful of distributions recognized by the Free Software Foundation as completely free. Blag recently released a new version based on Fedora 14, two and a half years after its last release.
Although Fedora and its spins are usually available as Live Media, derivatives designed specifically to be run as Live Media are relatively rare. A Japanese derivative called Berry appears to be the only one designed for general use as a demo.
Other Live Media derivatives are more focused. For example, the Network Security Toolkit is a collection of most of the applications listed in the list of Top 100 Network Tools. The Rocks Cluster Distribution is even more specialized, offering a clusters solution that is easy for beginners to use while containing enough advance features to satisfy an expert.
Fedora supports a large number of Asian derivatives. No doubt the main reason for these derivatives is the RHEL-based Asianux, an enterprise solution for Asian languages developed by Red Flag, the largest Chinese Linux distribution, Miracle Linux Corporation of Japan and Hancom Linux of South Korea.
Other Chinese derivatives include NeoShine, Linpus, and the community-based Magic. Other Asian localizations include the Korean Annyung and the Japanese Niigata. Most of these derivatives emphasize server installations, with Linpus making some effort to focus on netbooks, with MeeGo editions designed for regular desktops and touch screens.
Besides these Asian examples, localized Fedora derivatives include Bee (Algerian), Ojuba (Arabic), Linux XP (Russian), and Sulix (Hungarian). In contrast to the Asian localizations, these are focused largely on the desktop and the individual user, especially in education.
Hardware Specific Distributions
Another specialty for Fedora derivatives is mobile and other hardware platforms. For example, the Russian ASPLinux is designed not only for porting applications to and from Linux, but also for developers working with embedded systems.
Userful Desktop, a Canadian derivative, is customized for running multiple terminals from a single computer, a feature popular in education and public institutions such as libraries. Another customized derivative is One Laptop Per Child (OLPC), whose efforts to empower children in developing countries was a popular cause a few years ago.
Almost as well-known as One Laptop Per Child -- at least in free software circles -- is Yellow Dog Linux. Based on Fedora and CentOS, Yellow Dog is one of the distributions of choice for running GNU/Linux on Apple computers.
Security and Servers
With Fedora's inclusion of SE Linux for security and RHEL's emphasis on the server, it is only natural that a healthy number of their derivatives emphasize these areas.
Many derivatives are designed for general use as networks, gateways and general servers. They include ClearOS, IDMS Linux, Openwall, and SME Server. Others, though, are more specialized. For instance, Startcom is designed for small to middle-sized servers, while Phayonne specializes in USB storage devices for servers and TFM Linux in assisting new administrators, such as you might find in a small business, who are still learning their job
Among security-based Fedora derivatives, EnGarde is probably the best-known and most popular. Not only does Engarde provide still another level of security-hardening, but its remote administration tools have the reputation of being easy to use.
Almost as well known as Engarde is K12Linux. Formerly known as the Linux Terminal Server Project (LTSP), K12Linux is designed to set up a terminal server for administering thin clients. Since this system can extend the lives of older, low-end computers, K12 is especially popular in schools, non-profits, and any other organization with limited funds.
Fedora's derivatives also include several miscellaneous distributions. Another unusual derivative is VortexBox. Originally designed to be a music server that can interact with Windows, VortexBox also supports DVD moving ripping.
Other miscellaneous derivatives include Fermi and Scientific Linux. Co-developed by Fermi National Accelerator Laboratory and the European Organization for Nuclear Research (CERN), these are two related derivatives recompiled from RHEL for scientific work by specific organizations. Scientific Linux includes a number of non-standard filesystems, such as Cluster Suite, GFS, FUSE, and SquashFS, as well as enhanced wireless support, while Fermi is designed to set up a security-hardened version of Scientific Linuxs security-enhanced system quickly and easily.
This ecosystem of distributions may be smaller than Debian's, but it is still large enough to satisfy most users. The main differences are a relative lack of multimedia distributions among the Fedora derivatives, a greater emphasis on security in Fedora, and a difference in the emphasis of localizations -- where Debian is popular in Spanish and Portuguese-speaking countries, Fedora has the edge in Asian languages, especially Chinese.
As with Debian derivatives, if you can't find what you want among Fedora and its off-shoots, then you probably haven't looked hard enough. However, Fedora does have one definite advantage: if you really can't find what you need, you don't need to be an expert to create it yourself. That's a feature that might easily offset Debian's otherwise much greater influence.