This looks really neat

Very cool! One small point of pedantry:

> A tree with multiple inheritance (sometimes called tangled tree) cannot be represented by using a classic tree visualization. It is technically a directed acyclic graph (DAG) with one (or more) nodes identified as root.

What is the difference between a DAG and a tangled tree? Isn't any DAG a tangled tree? I don't see immediately why a new definition is required.

I'm not entirely familiar with tangled trees, but it seems like one of the larger differences is that a tangled tree isn't necessarily acrylic. For this example, someone could navigate away from one page, but potentially be linked back to it later down the adventure.

> A tree with multiple inheritance (sometimes called tangled tree)

By the author's definition, multiple inheritance prohibits cycles. DAGs can be modeled as tree with back edges to non-ancestors. So I'm pretty sure tangled tree = DAG.

> For this example, someone could navigate away from one page, but potentially be linked back to it later down the adventure.

Good point, maybe "tangled tree with back edges to ancestors" is the really correct model for what the author wants. The key point of the visualization is to highlight the deviation from a standard DAG or tree.

The author already says that:

> It is technically a directed acyclic graph (DAG)

But DAG's don't have 'roots', they just have nodes. The concept of roots makes it a tangled tree.

Is there a source code for the visualization?

That's a live notebook! If you click on the cells, you can see the code that was used to create it, like a Jupyter notebook.

Ah, thanks! Wasn't that obvious on mobile.