bitmap font facility that allows painting text onto
      images.  We currently support one font in several sizes.
      The font images and postscript programs for generating
      them are stored in prog/fonts/, and also as compiled strings
      in bmfdata.h.

    - a binary maze game lets you generate mazes and find shortest
      paths between two arbitrary points, if such a path exists.
      You can also compute the "shortest" (i.e., least cost) path
      between points on a grayscale image.

    - 