bindings to Graphviz for graph visualization

 This library provides bindings for the Dot language used by the
 Graphviz (http://graphviz.org/) suite of programs for visualising
 graphs, as well as functions to call those programs.
 .
 Main features of the graphviz library include:
 .
 Almost complete coverage of all Graphviz attributes and syntax.
 .
 Support for specifying clusters.
 .
 The ability to use a custom node type.
 .
 Functions for running a Graphviz layout tool with all specified output
 types.
 .
 The ability to not only generate but also parse Dot code with two
 options: strict and liberal (in terms of ordering of statements).
 .
 Functions to convert FGL graphs and other graph-like data structures
 to Dot code - including support to group them into clusters - with a
 high degree of customisation by specifying which attributes to use
 and limited support for the inverse operation.
 .
 Round-trip support for passing an FGL graph through Graphviz to
 augment node and edge labels with positional information, etc.
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.