What options are available for the layout of directed or undirected graphs in .NET?

Question

By graph here I mean something resembling these images:

Answer 1

I am working in the NDepend team and I confirm: we switched from GraphViz to MsAgl in september 2008 and also the MsAgl license allows indeed commercial utilisation. Here are a few sample pictures of MsAgl graphs integrated in NDepend (everything is interactive, nodes are movable/selectable/removable/clickable, edges are editable/selectable/removable/clickable, the layout is zoomable, and also, while it could be cleaner the MsAgl API is clean enough to work with):