Finally, the new DeepaMehta version has been released. It will not resonate with everyone. But if you appreciate mapping tools and have not yet found what you want, give it a try.
Although I am not affiliated with this open source project other than helping with tests and documentation, I really need to advocate for it. See
It is not my every day tool, but if the conceptual connections between text snippets or ideas are weak or complex, it is more effective than every other tool I know.