- HTML to markdown: Jina AI Reader

- Markdown to Graphviz DOT: LLMs

- Graphviz DOT to SVG: Viz.js

- Data Storage: TSV files

- Document updating: GitHub Actions

- Frontend: HTML + CSS + Vanilla JS

There are also side tools linked at the bottom of the ChartHN page:

- a web tool to convert any page to a diagram

- a visual benchmark to compare the performance of LLMs in generating Graphviz DOT data

To fit Graphviz DOT data within a TSV file and reduce file size, I have also developed dot-minify (https://github.com/cxumol/dot-minify) as a sub-project. This is likely to be the world's first tool to minify Graphviz dot format data, according to my research.