SDF Public Access Unix System

Super Dimension Fortress (abbreviated as SDF, also known as freeshell.org) is a non-profit public access UNIX shell provider on the Internet. It has been in continual operation since 1987 as a non-profit social club. The name is derived from the Japanese anime series Super Dimension Fortress Macross; the original SDF server was a Bulletin board system created by Ted Uhlemann for fellow Japanese anime fans.^[1] From its BBS roots, which have been well documented as part of the BBS: The Documentary project, SDF has grown into a feature-rich provider serving members around the world.