SDF Public Access Unix System
Super Dimension Fortress ( SDF, also known as freeshell.org ) is one of the oldest and largest nonprofit provider access for Unix systems on the Internet. Server locations are Texas, USA, and Falkenstein in Germany.
SDF is operated as a kind of non-profit organization since 1987. The name is derived from The Super Dimension Fortress Macross, because the server originally served as a BBS for fans of anime.
The association currently (February 2008), more than 30,000 users from around the world, including students, engineers, programmers and artists.
Services
SDF is run on NetBSD servers. In addition to shell access, which can be activated against a registration fee of currently € 5 or 1 USD paid memberships for hosting, VPN, domain registration, DNS will be much more. offered. SDF is one of the few public servers still offer the Gopher protocol.
The free base access already provides access to all the main programs of the system and 200 MB disk space for user directory, simple web pages, emails and Gopher. After the paid validation of the access will be unlocked on other software, and with the acquisition of additional membership levels will increase the available disk space.
From a certain membership level members will be given a say in the services offered. Thus the quotas for traffic and storage space were repeatedly raised in the past. Members undertake to accept in the use of services offered terms of use, if neglected, can lead to exclusion by the community.
The association offers educational institutions free access for UNIX courses.