The Free On-line Dictionary of Computing (30 December 2018):

ezd

    (Easy drawing) A graphics server that sits
   between an application program and an X server and allows
   both existing and new programs easy access to structured
   graphics.  Ezd users have been able to have their programs
   produce interactive drawings within hours of reading the
   manual page.  Ezd supports structured graphics - application
   defined graphical objects are ordered into drawings by the
   application.  Unlike most X tools, ezd does not require any
   event handling by the application.  The ezd server maintains
   the window contents.  When an event occurs an application
   supplied Scheme expression is evaluated.

   (ftp://gatekeeper.dec.com/pub/DEC/ezd/).

   Contact: Joel Bartlett.

   (2000-03-25)