I am looking for a simple graph layout library for C++. I want to embed the library into our visualizer based on wxWidgets. In summary, I am looking for something like graphviz, except dynamic - that is when an event occurs, only the change in graph needs to be loaded, not the complete display. There is dynagraph, but it seems a dead project. I have previously been suggested to use VTK - but it is a heavyweight.
I am looking for open source, non-copyleft kind of library available for commercial use (GPL is out, LGPL should be ok). I am open to suggestions that google won't give.