Laying out the verticies in a DAG in a tree form (i.e. verticies with no in-edges on top, verticies dependent only on those on the next level, etc.) is rather simple without graph drawing algorithms such as Efficient Sugiyama. However, is there a simple algorithm to do this that minimizes edge crossing? (For some graphs, it may be impossible to completely eliminate edge crossing.) A picture says a thousand words, so is there an algorithm that would suggest something without crossing edges. (compared to this).
EDIT: The result
I've accepted Senthil's suggesting graphviz/dot -- a quick look at the docs confirms that it's very easy to use it as a library or external tool, and the output format is surprisingly easy to parse. However, I ended up choosing to use GraphSharp instead since I'm already using .NET, etc (though it's definitely not as powerful as dot). The result is "good enough", and could be made a lot better with a little edge routing and tweaking (the blurry text is because of 3.5 WPF).
