[throwaway1918]

He was not a professor. He quit his job at MIT (as some sort of staff researcher/programmer) in 1984 to start the GNU project. He was an unpaid visiting scientist and had an office, although he was rarely in it (he spends a lot of time traveling). He did not have any institutional power beyond his participation as a rando on the mailing lists.

[roywiggins]

You're right, he was a "visiting scientist", whatever that means.