It's what mathematicians[0] and programmers[1] refers to as a graph. Traditionally you would use http://graphviz.org/ http://graphviz.org/ and its many derivati

It's what mathematicians[0] and programmers[1] refers to as a graph. Traditionally you would use http://graphviz.org/ http://graphviz.org/ and its many derivatives, which meets your long-term-stable criteria. These days if you want clicky web GUI you can use a bunch of javascript-ports, eg. https://sketchviz.com/new https://sketchviz.com/new or https://github.com/jwilber/roughViz https://github.com/jwilber/roughViz ... avoid valuing presentation over content, though. [0] https://en.wikipedia.org/wiki/Graph_(discrete_mathematics) https://en.wikipedia.org/wiki/Graph_(discrete_mathematics) [1] https://en.wikipedia.org/wiki/Graph_(abstract_data_type) https://en.wikipedia.org/wiki/Graph_(abstract_data_type)