Original pyan.py for Python 2 by Edmund Horner, 2012. Original blog post with explanation.
Coloring and grouping for GraphViz output by Juha Jeronen.
Git repository cleanup and maintenance by David Fraser.
yEd GraphML output, and framework for easily adding new output formats by Patrick Massot.
A bugfix [2] and the option --dot-rankdir [3] contributed by GitHub user ch41rmn.
A bug in .tgf output [4] pointed out and fix suggested by Adam Eijdenberg.
This Python 3 port, analyzer expansion, and additional refactoring by Juha Jeronen.
HTML and SVG export by Jan Beitner.
Support for relative imports by Jan Beitner and Rakan Alanazi.
Further contributions by Ioannis Filippidis, Jan Malek, José Eduardo Montenegro Cavalcanti de Oliveira, and Mantas Zimnickas.