The Tree::Nary class implements N-ary trees (trees of data with any
number of branches), providing the organizational structure for a
tree (collection) of any number of nodes, but knowing nothing about
the specific type of node used.  It can be used to display
hierarchical database entries in an internal application (the NIS
netgroup file is an example of such a database). It offers the
capability to select nodes on the tree, and attachment points for
nodes on the tree. Each attachment point can support multiple
child nodes.

WWW: http://search.cpan.org/dist/Tree-Nary/