Task Modeler is an IBM-produced, Eclipse-based software tool for modeling human activity as a hierarchy of task and related elements.
An information architect can use Task Modeler to design DITA maps. A usability practitioner can produce either classic HTA (Hierarchical Task Analysis) diagrams or RAG (Roles and Goals) diagrams.
For more information
For more information about Task Modeler, see http://www.alphaworks.ibm.com/tech/taskmodeler.
The Task Modeler download contains Eclipse version 3.0 with Task Modeling and XML file editing (XMLBuddy) already configured.