# What is Debian? Debian is an operating system which is composed primarily of free and open-source software, most of which is under the GNU General Public License, and developed by a group of individuals known as the Debian project. Debian is one of the most popular Linux distributions for personal computers and network servers, and has been used as a base for several other Linux distributions. > [wikipedia.org/wiki/Debian](https://en.wikipedia.org/wiki/Debian) %%LOGO%% # About this image The `debian:latest` tag will always point the latest stable release (which is, at the time of this writing, `debian:jessie`). Stable releases are also tagged with their version (ie, `debian:8` is an alias for `debian:jessie`, `debian:7` is an alias for `debian:wheezy`, etc). The rolling tags (`debian:stable`, `debian:testing`, etc) use the rolling suite names in their `/etc/apt/sources.list` file (ie, `deb http://httpredir.debian.org/debian testing main`). ## `/etc/apt/sources.list` The mirror of choice for these images is [httpredir.debian.org](http://httpredir.debian.org) so that it's as close to optimal as possible, regardless of location or connection. $ docker run debian:jessie cat /etc/apt/sources.list deb http://httpredir.debian.org/debian jessie main deb http://httpredir.debian.org/debian jessie-updates main deb http://security.debian.org jessie/updates main