> Second, if Haskell should be more successful in the
> real world there has to be a way of demonstrating
> basic ideas of a big program to "customers". How
> would you do this? Everybody knows UML class
> diagrams, for example. In contrast, nobody knows
> about termgraphs or lambda *g*.

The UML is not executable, draw a pretty picture. No one knows UML,
everyone knows pretty pictures - most people can guess at the meaning
of UML because they know the meaning of pictures. As to reverse
engineering a diagram from code, that always leads to ugly (and
pointless) diagrams.