Slackware

Slackware is a Linux distribution, created by Patrick Volkerding in 1993. It was based on Softlanding Linux System, Slackware has been the basis for many other Linux distributions, most notably the first versions of openSUSE distributions, and is the oldest distribution that is still maintained.

Slackware aims for design stability and to be the most "Unix-like" distribution of Linux. Slackware is mostly free and open source software, while it doesn't have a bug tracking facility or public code repository.