My almamater, Grinnell College, has a still active social network Grinnell Plans, which extended from .plan usage for social networking on the college's Vax computer system.
Nice to see a another Grinnell alum in the wild! I want to try plans, but lost access to my @grinnell.edu email after I graduated. What do you think about it? Should I check it out?
https://www.grinnellplans.com/documents/faq.html