What layout should I use?

What layout do you suggest for building something like this (which will be dynamically built), user will click the “+” and the dependencies will be added via ajax call.

I am currently using graphviz (quick and dirty). Here is an example of what I want to switch to GoJS

LayeredDigraphLayout:

Although you might want to consider other layouts such as ForceDirectedLayout: GoJS Layouts -- Northwoods Software