The name MrEd was also an in-joke because Matthias Felleisen was notoriously anti-TV, so his students thought it fun to sneak in a TV reference. Lots of the ol

The name MrEd was also an in-joke because Matthias Felleisen was notoriously anti-TV, so his students thought it fun to sneak in a TV reference. Lots of the old subsystems had prefixed-names. MrEd and MzScheme begat DrScheme; others include SrPersist (Sister Persist) and FrTime (Father Time). We built a debugger called MzTake ("when you make a mistake, use MzTake"). My favorite is an IRC client that Robby Findler wrote called MzCommunication.