I have used both Pikchr and several of the Mediawiki extensions for diagrams (the most recently-maintained of which is https://www.mediawiki.org/wiki/Extension:Flex_Diagrams )

Here is my earliest Pikchr effort: https://lumosql.org/src/not-forking (click to see source.)

Pikchr diagrams are crisp and precise with zero configuration. Mermaid diagrams are difficult to make render as nicely as the screenshots show (https://mermaid-js.github.io ) and easier to confuse with ambiguous syntax.

With the addition of 5 lines Lua, Pandoc now handles Pikchr in Markdown documents: https://groups.google.com/g/pandoc-discuss/c/zZSspnHHsg0/m/m...