Softlanding Linux System (SLS) was one of the first Linux distributions, and the first "massive" and "comprehensive" Linux distribution to contain not just the Linux Kernel and basic utilities, but some of the early GNU/Linux ports such as the X Window System and TCP/IP. It was founded by Peter McDonald in mid-1992.
SLS was probably the most popular Linux distribution at the time, but was also viewed by the community as being buggy and poorly maintained. Two of the more well-known critics of SLS were Ian Murdock and Patrick Volkerding. Murdock's frustration with SLS lead him to create the Debian project, while Volkerding decided to fix the problems with SLS and eventually renamed his work Slackware.