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

Microsoft Research provides a tool called MSAGL (Automatic Graph Layout, previously called GLEE) for .NET.

MSAGL is available here: http://research.microsoft.com/en-us/downloads/f1303e46-965f-401a-87c3-34e1331d32c5/default.aspx

Disclaimer: I haven't used the tool so I don't know whether it is suitable for you (and neither do I know about the licensing conditions, seems it is for non-commercial applications only). But at least it looks interesting.