--- /dev/null
+This set of scripts scans a Python file for module dependencies, and
+generates code for [Graphviz dot][graphviz].
+
+Originally by Toby Dickenson. Good for giving you the "long view" on
+how your project is organized. I've [altered][] the [originals][] a
+bit.
+
+My `py2depgraph` also prints out path information for each module, so
+that you can show or hide module nodes based on those paths. For
+example, ignoring system modules to focus on your additions.
+
+My `depgraph2dot` has an added method
+`depgraph2dot.invalidpath(module_name, path)` that you can override to
+determine the paths you like.
+
+I've also added the `depgraph2dot` methods
+
+* `is_Cext(module_name, path)`,
+* `Cext_depends(module_name, path)`,
+* `Cext_edge_attributes(module_name, Cext_name)`,
+* `Cext_node_attributes(Cext_name)`, and
+* `Cext_depcolor(Cext_name)`
+
+to detect and configure the shared C libraries extending Python, so
+you know where to look for the code your Python depends on.
+
+As example, here is the depgraph of my protein unfolding program [unfold.py][]
+
+ $ python py2depgraph.py unfold.py | python depgraph2dot.py | dot -T png -o depgraph.png
+
+with standard python modules in orange,
+python packages in hash-based colors,
+and C extension modules in light blue.
+Again, these are only the files containing either `wking` or `comedi`
+in their paths.
+
+[[!img depgraph.png class="scaled"
+ alt="unfold.py dependency graph"
+ title="unfold.py dependency graph"]]
+
+[graphviz]: http://www.graphviz.org
+[altered]: http://www.physics.drexel.edu/~wking/code/git/git.php?p=depgraph.git
+[originals]: http://tarind.com/depgraph.html
+[unfold.py]: http://www.physics.drexel.edu/~wking/code/git/git.php?p=unfold_protein.git
+
+[[!tag tags/tools]]
+[[!tag tags/programming]]