https://drawnix.com/
https://github.com/plait-board/drawnix

https://excalidraw.com/
https://github.com/excalidraw/excalidraw

draw.io
https://app.diagrams.net/

https://mermaid.js.org/
Mermaid
Mermaid is ideal for those who prefer writing diagrams in Markdown-like syntax, offering a developer-friendly approach.

ZenUML
ZenUML excels in creating interactive and visually appealing diagrams that can be directly linked with your codebase.

diagram as code in python
https://diagrams.mingrammer.com/
https://github.com/mingrammer/diagrams

mermaid for github repo
https://gitdiagram.com/