I haven't decided. The intent is actually to map network traffic (i.e., one part captures traffic, stores the packets locally, and sends summary information to a server where another part of the app can access it to develop interactive maps and charts to evaluate the information). It currently has no concept of routers, switches, etc. but is focused on the traffic itself.
I have a SourceForge page for it (search Google for Flower NFA), but haven't updated the code there in many months. The code I have locally works well to generate flow maps and volume histograms.
It's a bit fragile, and still needs a lot of work, but it's coming together. If you'd like to try it out, e-mail me at email@example.com. You'll need a Debian box for the capture portion (it's written in Python) and a Glassfish v3 server for the Analysis and Visualization components (Java). I run all portions virtualized in two servers (Debian and Windows 2008) on a single XenServer.