I reached the same conclusion after comparing diagram-as-code tools — D2 feels cleaner and more expressive than Mermaid.

I’ve been working on an AI diagramming tool built around D2: https://aidiagrammaker.com/ You describe a system in plain English, and it generates architecture diagrams, flowcharts, and sequence diagrams in D2.

Edits can be made either directly in the D2 code or via a context-aware editor.

Has anyone here used https://pikchr.org/ from the creator of SQLite?

I agree that it's nicer and more powerful, but it's a little concerning it hasn't had any commits in the past 6 months: https://github.com/terrastruct/d2/commits/master/

Thanks for sharing! I haven’t looked into that before but looks neat.

Oh, finally, something that supports actual hierarchical state diagrams (that isn't Graphviz, no offense)... Mermaid's "You cannot define transitions between internal states belonging to different composite states" [1] has driven me up a wall for years.

  parentA.childA -> parentB.childB: voop
  parentB.childB -> parentA: vorp 

shouldn't be that hard!

[1] https://mermaid.ai/open-source/syntax/stateDiagram.html#comp...

Does it produce real svgs as opposed to foreign object html in svg mess that mermaid compilers produce?

What makes it nicer?

How good is the LLM at creating d2? What if any skills/material can folks recommend? (Follow-up: D2-mcp has a cheat sheet, https://github.com/h0rv/d2-mcp/blob/main/d2/CHEATSHEET.md)

And, does GitHub support it? (Follow up: alas not! Sadness. Please add!)