@ben @dwenius The people running undergrad computing at the time were obsessed with controlling load (and to be fair, they only had overloaded Vaxen). We had a much friendlier locally customized ed ('UofT ed') and that was what you mostly got to use.
Later they introduced a curses-based editor built to work with the teaching language ('Turing', which eventually got commercialized for this by a UofT spinoff). I'm pretty sure it was less system-efficient than eg vi, but it was Official.