The unstable distribution (sid) The code name for Debian's development distribution is sid, aliased to unstable. Most of the development work that is done in Debian, is uploaded to this distribution. This distribution will never get released; instead, packages from it will propagate into testing and then into a real release.

Don't let the name fool you. While Debian Unstable might sometimes happen to introduce some bugs or regressions with it's updates, it surely isn't as 'Unstable' as name would suggest. Debian Unstable is made mostly of stable releases of software packages, not development versions as one might think at first. Adding further to this, regular Ubuntu releases are based on Debian …

Debian has three different branches: (1) stable, (2) testing and (3) unstable. The unstable branch "Sid" is a rolling release distribution similar to someth...

Debian Unstable (also known by its codename “Sid”) is not strictly a release but rather a rolling development version of the Debian distribution containing the latest packages. Debian Unstable is one of the three distributions Debian provides (along with Stable and Testing).

Debian « unstable » (connu aussi sous le nom de code Sid) n'est pas à proprement parler une version de Debian mais plutôt une publication continue de la distribution renfermant les paquets les plus récents et les meilleurs qui viennent d'être introduits dans le système Debian. Si vous êtes un développeur ou un testeur irréductible, vous devriez utiliser cette version.

Both Debian and Ubuntu build their releases from Debian unstable. They take the current set of packages from Debian unstable (more or less — they ensure that they have a consistent set, whereas Debian unstable can break e.g. when a new version of a library gets in and the software that relies on it hasn't been updated yet).

Debian unstable/experimental is a lot more stable than Ubuntu, guaranteed in years of desktop usage. Sometimes it can break some package, but you don't have to upgrade everytime, and downgrading desktop packages is often safe. Upgrading a Debian unstable is also safer than upgrading an Ubuntu release in my experience.

It is recommended that users running unstable should subscribe to the debian-devel-announce mailing list to receive notifications of major changes, for example upgrades that may break. The unstable distribution is always called sid. Release life cycle. Debian announces its new stable release on a regular basis.

The Debian developer will upload the package to unstable. In unstable , it will immediately become available to anyone using that release. After a several days in unstable , and once a set of criteria has been met (like no new bugs filed of a certain priority, ...), a system move it automatically to testing .