I'm looking for either algorithms or visualization tool for (nice) circuit/block-diagram drawing.

I am also interested in a general formulation of the problem.

By "circuit drawing", I mean the capability of exploring place & route for block-diagrams (rectangles) with I/O ports and their connections (wires). These block-diagrams can be hierarchical i.e some blocks may have some nested internal sub-structure etc.

This topic is strongly related to classical graph-drawing, with the supplemental constraint of the need to take ports location into account, and possibly the shape of the blocks (rectangle of various sizes). Graphviz tools do not respond to the problem (at least my previous experiments have not been satisfactory).

Force-directed algorithms retain my attention, but I have just found papers on classical directed graphs.

Any hints ?