Show HN: Line9 – A Mermaid rendering engine with its own layout(line9.ai)
77 pointsby jumpalongjim6 days ago13 comments
  • hankbond10 hours ago
    I have a bunch of bad layouts so I'll give it a shot, but there's no way my org would pay 120 a year per seat for this. I don't think for any price it would get through procurement to be honest. Also we mostly render mermaid in confluence documents with a macro that renders it from the source in the document. Not sure how that would relate to this pricing/auth model.

    Not trying to throw any shade or dissuade you from trying to earn a living, just providing feedback.

    • xdotcommer9 minutes ago
      I dunno... This may not be for everyone but if I consider the amount of time spent correcting diagrams in excalidraw $10 / month seems more than reasonable to me: as long as it's for the creator not the viewer.
    • jumpalongjim3 hours ago
      Thanks. I haven't yet got to looking into Confluence. I used to use a Confluence plugin for Lucid charts and I guess something like that for Line9 would be useful if it gets much traction. I don't know whether the embedding options in the Pro account would display well in Confluence.

      On pricing, I'm testing numbers at the moment so your feedback is valuable. Anyway, please do paste in your bad layouts - I'd love to hear what happens.

      • bberenberg29 minutes ago
        I’m the author of one of the most popular mermaid renderers in Confluence. People spent huge sums of money on this. Feel free to message me if you have questions about the space.
  • sbarre10 hours ago
    FYI for any new or casual Mermaid users, it comes with a built-in alternate layout called `elk` that I find does a much cleaner job on complex flowcharts.

    See docs here: https://mermaid.ai/open-source/config/layouts.html

    • ramoz8 hours ago
      I'm trying some of the diagrams in elk and it seems to break the logical flow.

      You can try it with Line9's first chart: https://mermaid.ai/live/edit#pako:eNpVVEtv2zAM_iuCTilgB1mbxq...

      While it's nice and compact, it actually is rougher to grep.

    • CGamesPlay9 hours ago
      This is super interesting, but apparently neither Obsidian nor Typora include support for it. I guess it's actually provided by an optional plugin.

      https://mermaid.ai/live/edit#pako:eNplUlFPwjAQ_ivNPW9EkMHWB4...

    • jumpalongjim3 hours ago
      Mermaid does indeed provide alternative layout engines. Please do try ELK before Line9. My experience is 1) hand-tuning the layout of Mermaid, having to try alternative engines or parameters, is not what I want. I just want a graph that I can use straight away. 2) ELK more often than not does give a clearer flowchart that I might be satisfied with for personal use but I still wasn't happy putting it in a presentation in front of others.
  • WalterGR11 hours ago
    Graph layout is a very interesting, very hard problem.

    There's even a yearly competition - started in 1994 - whose results are announced at the yearly Symposium on Graph Drawing and Network Visualization.

    It's not a subject I'm versed in, but can you talk more about your solution? Do you use a larger constraint solver or is it hand-coded?

    --

    Competition: https://mozart.diei.unipg.it/gdcontest/

    The 34th International Symposium on Graph Drawing and Network Visualization, to be held in Ontario, Canada: https://graphdrawing.github.io/gd2026/

    n.b. It's an independent conference, not under the auspices of e.g. IEEE or ACM.

    • jumpalongjim4 hours ago
      Neither, really — it's closer to hand-rolled local search.

      My first three phases are based on Sugiyama to produce a seed layout (which is broadly what Dagre does). Then I've added my new phases driven by a penalty score that grades candidate layouts using fourteen factors that I devised from my experience laying out graphs manually. The refinement phase is where the bulk of my work is. It applies targeted move types iteratively within a budget, trying to lower the penalty score.

      Finally, the result goes through my own embedding and rendering with the theme system on top.

  • h2aichatan hour ago
    Great idea! I will definitely try it with some graphs that could benefit from it.
  • nylonstrung9 hours ago
    https://frankorz.com/merman/ Here's a pretty solid Rust reimplementation of Mermaid btw
  • albert_e2 hours ago
    Tangent

    What is the current standard for generating valid BPMN diagrams. Does Mermaid support the level of control needed for formal diagrams of this nature with possible L1/L2/L3 drill down, multiple swimlanes, etc.

  • iamcoder1811 hours ago
    This solves my biggest gripe with Mermaid.

    It's an amazing tool, but I wish it were open source.

  • romanhotsiy4 hours ago
    It doesn't work with 4 of 5 diagrams from our codebase I tried randomly :(
    • jumpalongjim3 hours ago
      Oh dear, sorry that didn't work out well for you. If you’re pasting flowcharts that don’t work then I really want to try to address them. Can you say what happened? Nothing rendered at all, or something you couldn’t use? If you’re able to send them to me directly they’re worth a lot as real diagrams to improve Line9 from.
  • ryanackley11 hours ago
    Looks cool. Price is pretty steep. Lucid chart is like $16/month.
  • rdwrrr6 hours ago
    I regret learning mermaid. The ecosystem is absolutely terrible.
    • jumpalongjim28 minutes ago
      I'd separate Mermaid the language from the tooling around it. The language has real strengths, like Markdown for diagrams, and not least in being ubiquitous so that both humans and AIs can use it easily. What I found poor was the tooling side and that's what prompted me to create a new layout engine. The ecosystem can be improved.
  • 11 hours ago
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  • mewens5 hours ago
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  • MnemosyneOS5 days ago
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