Dot-Import for Blender:

Features:
-Import *.dot-Files from graphivz and generate Curves
-Group generated curves
-apply a hook-modifier to ends of edges, so you can move nodes later.

Manual:
This script imports graphviz dot Files into Blender. It uses graphviz the locations
generated from graphviz for positions. The RAW-plugin is used as template.

Setup:
copy all files to:
create a new folder in 2.56/scripts/addons (ex. io_import_dot)
copy all downloaded files to this folder

Usage:
Generate a dot graph "input.dot". (see graphviz homepage: www.graphviz.org, and sample.dot)
Run dot without -T option on this graph "dot -o output.dot input.dot"
Execute this script from the "File->Import" menu and choose "output.dot" file to
open.

Notes:
no html-formating is done, importer is really simple at the moment.

wiki-site: http://wiki.blender.org/index.php/Extensions:2.5/Py/Scripts/Import-Export/dot_import