Load data in the TreeML format, which was created by Jean-Daniel Fekete and Catherine Plaisant to support the InfoVis 2003 Contest. The TreeML format is described here: http://cs.marlboro.edu/courses/fall2006/tutorials/information_visualization/TreeML and has a DTD here: http://www.nomencurator.org/InfoVis2003/download/treeml.dtd
The tree data can of course be used in all graph algorithms as well as tree algorithms.
Pros & Cons
WARNING: The current implementation of TreeML reader does not support leaves hanging directly from the root of the tree. All leaves must be under branches. Future versions should correct this problem.
The format is verbose and relatively obscure, but also a simple and easily understandable way of describing tree structures.
This algorithm wraps the Prefuse TreeML reader.
Jean-Daniel Fekete and Catherine Plaisant, for creating the format