Slackware is a free and open source operating system. It is one of the earliest and currently maintained distribution of GNU/Linux. Slackware was released in 1993 and the creator is Patrick Volkerding. Slackware is one of the most "Unix" like Linux distributions. The focus is on design stability and simplicity. The latest release version of Slackware is 13.0. The Slackware distribution is definitely not the most user friendly for beginners but it is a very good distro. If you are looking to expand your knowledge of GNU/Linux than try out Slackware. It has a long history and a very strong following. Slackware is reliable, stable and has good performance. The latest release 13.0 has support for 64 bit architecture. The installation is text based and Slackware uses the KDE 4.0 graphical desktop enviornment. To download Slackware go to their website. Just don't forget that it is not the most user friendly distribution to start off with for new people to GNU/Linux.