MermaidJS now fully supported
You can now use MermaidJS, which is a diagramming and charting tool that renders Markdown-inspired text definitions to create diagrams dynamically, anywhere you use Markdown in CoCalc: text between code cells in Jupyter notebooks, whiteboards, slideshows, Markdown files, etc. Just put the mermaid diagram description in a fenced code block, like this:
and it will get rendered like this:
Using Mermaid in exactly this way is also fully supported in JupyterLab and on GitHub. Moreover, if you publish documents on the CoCalc share server, Mermaid also gets rendered properly, e.g., see these examples: