Hierarchy

Nodes in FreeMind are organized in pure hierarchy, meaning that each node other than the single root node has exactly one parent. This contrasts to directed acyclic graphs and to general graphs, found in diagramming software and in drawings of office suites such as MSO Office and OpenOffice.org.

Extensions beyond hierarchy could include having several root nodes in a mind map, having node clones, and having nodes with several parent or semi-parent nodes.

Nodes located in different branches can be connect using arrow links, which satisfies some of the requirements for going beyond hierarchy.

Discussion

• "Moving beyond pure hierarchy - pros & cons", 2008-03-18, Open Discussion
• "Tree versus DAG/Graph", 2003-10-22, Open Discussion