1. A computer-implemented method for visually presenting, simultaneously in the same graphical representation, both hierarchical relationships among, and non-hierarchical type information for, a plurality of data objects, the method comprising: determining for each data object an associated node type, thereby populating a plurality of node types, each node type corresponding to a single non-hierarchical type; creating a tree node for each data object, each tree node identifying the node type of the associated data object; and visually presenting in the graphical representation the tree nodes organized into a set of visually recognizable and distinguishable strata, each stratum encompassing a distinct region in the graphical representation corresponding to a single node type irrespective of a node's hierarchical position, said graphical representation presenting the hierarchical relationships among the tree nodes; wherein; in the graphical representation, a plurality of hierarchical connectors extend between tree node pairs; the hierarchical connectors represent hierarchical relationships between the data objects represented by the tree node pairs; and the graphical representation includes a boundary perpendicular to an axis along which at least some of the strata are arranged; said method further comprising: determining a target position associated with each depicted tree node, wherein the target position takes into account a pre-selected distance from the boundary, such that hierarchical connectors extending from the depicted tree node do not intersect any tree node not directly related to the depicted tree node and do not intersect any other hierarchical connector; and positioning each depicted tree node at its associated target position.