When I was a systems admin co-op at MIT Lincoln Laboratory, I coded my first web app that required a database, using MySQL and PHP. The Sign-Out Board is an interactive chart of names. It indicated, with red and green dots, who was "in" or "out" for that day. People could sign in and indicate their schedule with a clickable calendar. Our group consisted of approximately 90 people. This sign-out board was later used by other groups at MITLL.