Official, Semi-Official, and Unofficial Repositories
The Official Repository - Debian has several strict requirements for the software that it releases to be considered “free”. It is for this reason that not all of the software or documentation is available on the official repository. For example, there are certain documents that Debian uses that are not allowed to be altered or removed from the area that they are placed in so they are not considered to be free. Because of this reason, some people criticize Debian since they also have a non-free repository instead of excluding the proprietary software entirely. Then there are others out there who criticize Debian for separating the different non-free packages from the main repository. But, these strict requirements are what makes both the official and the unofficial repositories necessary.
Here are the different branches of the official repository and what they contain:
The non-free repository items have a license condition that restricts the use or redistribution of the software that it contains.
The contribution repository is freely licensed by the holder of the copyright, but it is still dependent on the other software that is in the non-free section.
The experimental repository is not quite a fully self-contained branch, but more like a temporary area for the extremely experimental software. There are dependencies that are missing here and are normally found in the unstable areas. There are warnings from Debian in this section that these packages are full of bugs and very unstable, so they are to be used at your own risk.
The volatile repository is where the updates to the stable and the oldstable releases are kept that require frequent updates. Some of the software packages here are aimed at fast moving targets, like spam filters or virus scanners, and they don’t always work completely at the full time of the next stable release. So, the main goal of this repository is to allow the system admins to update their systems in a consistent way without all the problems of using an unstable branch.
The Semi-Official Repository - In this area of Debian, users will find packages that have been complied from mostly testing and unstable cases only, which are usually the security updates. These will run with few to no libraries on the stable version, and sometimes on the oldstable. The packages that are listed here go hand-in-hand with the official repository’s items and branches that are found on www.debian.org, but the packages themselves are hosted at www.backports.org.
The Unofficial Repository - In this repository, users will find the packages that are more modern than the current ones in stable or include software packages that aren’t in the official Debian repositories for some reason, like a special too-restrictive license. These files require that users have a precise configuration of the priority of the repositories that are going to be merged together, or these software packages may not work right with the system and cause some program conflicts with other packages. The Debian project tries to discourage users from downloading and using these files as they aren’t from the project itself. Some of the more well-known repositories include: www.debian-multimedia.org and www.debian-unofficial.org.
Debian users can find all of these repositories by modifying the /etc/apt/sources.list file.
This post is part of the series: An In-Depth Review of Debian
For those Linux users who aren’t familiar with Debian, here is your BrightHub in-depth review to help you completely understand the system.