/usr/bin/script

  script -t 2> script.demo.time script.demo
  xemacs -nw
  # M-x tetris
  #            ; play tetris now
  # C-x C-c    ; exit emacs
  exit
  # watch tetris being played:
  scriptreplay script.demo.time script.demo

script can create a "screencast" of any terminal session. This works pretty well, but probably is not the right solution for the education market pg is talking about :-)