Thanks for the quick response.
I see what you are saying and why you chose the GPL. I suppose its just frustrating to have to re-think (or even think much about!) licensing when it hasn't been an issue for the bulk of my work.
The bits where I need the much better (and distributed) performance from your library is a graph generation/storage and analysis service.
It holds a bunch of graphs, quantifies topology on them, and identifies interesting groups of nodes/edges, returning the results via JSON (the analysis component needs to be able to run on a different machine from other bits of it - inputs are also JSON based API). Basically a generic "graph stuff" network service which implements the bits I need for the rest of the project.
From what I understand I can keep the original networkx version of this service and also develop a graph-tool version, the former staying with a BSD license and the latter having a GPL license.
However, one of my friends said that many would see that as "cheating" but it seems to be an intentional provision of the GPLv3 as far as I understand.
How would you view that scenario? Would you be OK with it or would you be upset/feel violated? Would your position change if I couldn't keep up maintaining both versions?
FYI I'm not a developer for any company, infact I'm not even a developer by trade (ex. pentester now security architect).