I love this documentary, and I agree with the comments. I never thought in my wildest dreams that someone would make a movie like this about such an important and nostalgic subject.
By using a modem, anyone else who knew the phone number of these computers could connect to them, leave messages, send and recieve files.... They called these places "Bulletin Board Systems", or BBSes.
php BB is a free flat-forum bulletin board software solution that can be used to stay in touch with a group of people or can power your entire website.