Fedora (pronounced /fəˈdɔrə/) is an RPM-based, general purpose operating system built on top of the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat. The Fedora Project's mission is to lead the advancement of free and open source software and content as a collaborative community.
One of Fedora's main objectives is not only to contain software distributed under a free and open source license, but also to be on the leading edge of such technologies. Fedora developers prefer to make upstream changes instead of applying fixes specifically for Fedora—this ensures that their updates are available to all Linux distributions.
Fedora has a comparatively short life cycle: version X is maintained until one month after version X+2 is released. With 6 months between releases, the maintenance period is a very short 13 months for each version. This can lead to trouble should one wish to use a particular version of Fedora for product development (ie: embedded systems) where long term support is more important than maintaining bleeding edge revisions of software.
In 2008, Linus Torvalds, author of the Linux kernel, stated that he used Fedora because it had fairly good support for the PowerPC processor architecture which he favored at the time.
According to DistroWatch, Fedora is the second most popular Linux-based operating system as of July 2010, behind Ubuntu.
The Fedora Project distributes Fedora in several different ways:
- Fedora DVD/CD set – a DVD or CD set of all major Fedora packages at time of shipping.
- Live images – CD or DVD sized images that can be used to create a Live CD or boot from a USB flash drive and optionally install to a hard disk.
- Minimal CD – used for installing over HTTP, FTP or NFS.
The Fedora Project also distributes custom variations of Fedora which are called Fedora spins. These are built from a specific set of software packages and have a combination of software to meet the requirements of a specific kind of end user. Fedora spins are developed by several Fedora special interest groups. It is also possible to create Live USB versions of Fedora using Fedora Live USB creator, UNetbootin or dd.
Extra Packages for Enterprise Linux (EPEL) is a volunteer-based community effort from the Fedora project to create a repository of high-quality add-on packages that complement the Fedora-based Red Hat Enterprise Linux and its compatible spinoffs such as CentOS or Scientific Linux.
Software package management is primarily handled by the yum utility. Graphical interfaces, such as pirut and pup are provided, as well as puplet, which provides visual notifications in the panel when updates are available. apt-rpm is an alternative to yum, and may be more familiar to people used to Debian or Debian-based distributions, where Advanced Packaging Tool is used to manage packages. Additionally, extra repositories can be added to the system, so that packages not available in Fedora can be installed.
Before Fedora 7, there were two main repositories – Core and Extras. Fedora Core contained all the base packages that were required by the operating system, as well as other packages that were distributed along with the installation CD/DVDs, and was maintained only by Red Hat developers. Fedora Extras, the secondary repository that was included from Fedora Core 3, was community-maintained and not distributed along with the installation CD/DVDs. Since Fedora 7, the Core and Extras repositories have been merged, hence the distribution dropping Core from its name. That also allowed for community submissions of packages that were formerly allowed only by Red Hat developers.
Also prior to Fedora 7 being released, there was a third repository called Fedora Legacy. This repository was community-maintained and was mainly concerned with extending the life cycle of older Fedora Core distributions and selected Red Hat Linux releases that were no longer officially maintained. Fedora Legacy was shut down in December 2006.
Third party repositories exist that distribute more packages that are not included in Fedora either because it does not meet Fedora's definition of free software or because distribution of that software may violate US law. The primary third party repository and the only fully compatible ones are RPM Fusion and Livna. RPM Fusion is a joint effort by many third party repository maintainers. Livna is still maintained separately as an extension of RPM Fusion for legal reasons and only hosts the libdvdcss package for encrypted DVD playback support.
Security is one of the most important features in Fedora. One of the security features in Fedora is Security-Enhanced Linux, a Linux feature that implements a variety of security policies, including mandatory access controls, through the use of Linux Security Modules (LSM) in the Linux kernel. Fedora is one of the distributions leading the way with SELinux. SELinux was introduced in Fedora Core 2. It was disabled by default, as it radically altered how the operating system worked, but was enabled SPARC.