Flowmeo is a web tool to quickly make one-way, "dependency" flowcharts (aka "directed acyclic graphs"), like you might need for designing an adventure game, or a tech tree, or a skill tree. I made it primarily as an aid for designing video games, but it could be useful for a planning a variety of different kinds of projects or systems.
You can try it out here: https://luvcraft.github.io/flowmeo/
Here's an overview video:
I built it using React (https://reactjs.org/) with Graphviz-React (https://www.npmjs.com/package/graphviz-react)
There is also a branch that uses mermaid.js (https://mermaid-js.github.io/), but it has rendering issues when graphs start getting big. You're welcome to clone this repo and run that version from the mermaid branch.
You can download the data from it as either JSON or DOT (Graphviz markup), and upload data as JSON. It's designed to be used as a planning tool rather than to generate scripts that you can use directly for game logic, although there's no reason you couldn't use the data for game logic with a suitable system.