 Besides offering free Unix shell access and web hosting to its users, SDF provides increasingly rare services such as dial-up internet access and Gopher hosting.SDF is one of very few organizations in the world still actively promoting the gopher protocol, an alternate protocol that existed at the introduction of the modern World Wide Web.The system contains thousands of programs and utilities, including a command-line BBS called BBOARD, a chat program called COMMODE, email programs, webmail, social networking programs, and developer tools.