Netron was written by a Belgian guy, who got frustrated no-one bought his library for big $$$ so we quited, and also removed ALL files from the sourceforge project as well.
I still have the original sourcecode here if you want it. It's not very good though, as in: it has lots of loose ends, commented out pieces etc. but it somewhat works. I changed a lot of code in it to make it working solid enough.
If you're looking for a library to create graphing functionality in your app, please use a commercial toolkit, as netron wont give a lot of joy . For example, there's no algo implemented to layout a graph properly, I have to do that myself.
Also the objects drawn are very low level, you've to draw every angle, line, shadow etc. and it's not vector oriented, just GDI+.
It works now for our toolkit as what we use in the lib has been changed here and there to make it do what we want.