Slackware is a free and open source operating system. It was one of the earliest operating systems to be built on top of the Linux kernel and is the oldest currently being maintained.
Slackware was created by Patrick Volkerding of Slackware Linux, Inc. in 1993. The current stable version is 13.1, released on May 24, 2010.
Slackware aims for design stability and simplicity, and to be the most “Unix-like” Linux distribution, using plain text files for configuration and making as few modifications as possible to software packages from upstream.
Secure Machine 