A library and an executable for working with derived Show
instances. By using the library, we can parse derived Show instances
into a generic data structure. The ppsh tool uses the library to
produce human-readable versions of Show instances, which can be quite
handy for debugging Haskell programs. We can also render complex
generic values into an interactive Html page, for easier examination.

Homepage:
http://hackage.haskell.org/package/pretty-show
