Graph editor

[Libra]

Hi,
I would like to build a simple graph editor, allowing me to add nodes
and edges via the mouse, along with the possibility to edit it (delete/
move nodes and edges, double click on object to pop-up a form where I
can insert object related info, and so forth) and bind edges to nodes
(that is, when I move a node, the attached edges move accordingly). I
should also put an image (a bitmap of png) in the background of the
graph.

I've seen many GUI libraries (from TkInter to wxPython) but I was
wondering if there is a specific graphic library (with good
documentation and maybe examples) simplifying the rapid development of
such an application.

Thanks
Libra