ETE is a Python programming toolkit that assists in the automated manipulation,
analysis and visualization of phylogenetic trees. It provides a wide range of
tree handling options, node annotation features and specialized features to deal
with phylogenetic trees (i.e automatic orthology and paralogy detection,
phylostratigraphy, tree reconciliation, etc). ETE implements also an interactive
tree visualization system based on a a highly customizable tree drawing engine
(PDF and SVG tree images). Although ETE is developed as a tool for phylogenetic
analysis, it is also used to handle other types of hierarchical trees
(i.e. clustering results).

WWW: http://etetoolkit.org/