Fedora Release Engineering Overview

The development of Fedora is a very open process, involving over a thousand package maintainers (along with testers, translators, documentation writers and so forth). These maintainers are responsible for the bulk of Fedora distribution development. An elected committee of people provides some level of direction over the engineering aspects of the project.

The rapid pace of Fedora development leaves little time for polishing the development system into a quality release. To solve this dilemma, the Fedora project makes use of regular freezes and milestone (Beta, Final) releases of the distribution, as well as "branching" of our trees to maintain different strains of development.

Stable branches of the Fedora tree and associated Repositories are maintained for each Fedora release. The Rawhide rolling development tree is the initial entry point for all Fedora development, and the trunk from which all branches diverge. Releases are Branched from Rawhide some time before they are sent out as stable releases, and the milestone releases (Beta and Final) are all built from this Branched tree.

Nightly snapshot images of various kinds are built from Rawhide and Branched (when it exists) and made available for download from within the trees on the mirrors or from the Koji build system.

The Fedora Release Life Cycle page is a good entry point for more details on these processes. Some other useful references regarding the Fedora release process include:

Various tasks need to be accomplished prior to a final Fedora release. Release Engineering is responsible for many of them, as outlined here.

Fedora “releases” are built using a set of tools available from the package repository. These tools aim to provide a consistent way to build Fedora releases, including the creation of network install images, offline install images ('DVDs'), live images, disk images, install repositories and other bits. A single run of the tools produces a set of repositories, images etc. referred to as a “compose”. In current Fedora, many of the compose tasks run in the Koji build system, so it is not straightforward to replicate the full compose process unless you have your own Koji instance and builders, but you can fairly successfully replicate individual image builds using the tools described below.

Once a compose has been completed, the composed tree of release media, installation trees, and frozen Repositories needs to be synchronized with the Fedora mirror system. has some more details on the mirror system. Many of the images are also offered via BitTorrent as an alternative method of downloading.

This document was influenced by release engineering documents from FreeBSD.