Rewriting Implementations

[N Ghani]

Is there any Haskell implementations of rewriting tools. This could be
any of string, term, equational or whatever forms of rewriting.

Also are there any Haskell packages including data structures for
algebriac objects like monoids, groups, rings, modules, graphs,
categories, enriched categories, K-algebras (ie monoids in K-modules),
kan extensions ....

Finally, are there any haskell packages for computing quotients of
such structures (perhpas using rewriting)

Neil