chronokun
...As for visualization, I think being able to provide sufficient information about the networks from the library would be enough for people to create visualizations trivially from that, but if you wanted, you could always include that either as a separate lib, or even just as an example usage application with code they can copy and reuse if they wish...
To expand on this thought, you could offer an API like dear imgui and just return a list of triangles/lines/primitives-of-your-choice that the user can handle rendering.