pez is a powerful, generic zipper library that can be used with a minimum of boilerplate, using fclabels lenses as an interface. This new version supports fclabels 1.0 and uses the new lenses supporting failure.
The API has changed significantly, but should be more stable at this point. You can try it with a:
$ cabal install pez
You can find the code on github here. I will try to post some fun examples here in the next week or two.