n.b. It's an independent conference, not under the auspices of e.g. IEEE or ACM.
jumpalongjim•Aug 12, 2026
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.
sbarre•Aug 12, 2026
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.
While it's nice and compact, it actually is rougher to grep.
jumpalongjim•Aug 12, 2026
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.
hankbond•Aug 12, 2026
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.
jumpalongjim•Aug 12, 2026
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.
I regret learning mermaid.
The ecosystem is absolutely terrible.
romanhotsiy•Aug 12, 2026
It doesn't work with 4 of 5 diagrams from our codebase I tried randomly :(
jumpalongjim•Aug 12, 2026
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.
albert_e•Aug 12, 2026
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.
9 Comments
It's an amazing tool, but I wish it were open source.
Just vibe code a user interface to it.
https://github.com/mermaid-js/mermaid https://github.com/mermaid-js/mermaid-live-editor https://github.com/mermaid-js/mermaid-cli
OP's product is not open source btw
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.
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.
See docs here: https://mermaid.ai/open-source/config/layouts.html
https://mermaid.ai/live/edit#pako:eNplUlFPwjAQ_ivNPW9EkMHWB4...
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.
Not trying to throw any shade or dissuade you from trying to earn a living, just providing feedback.
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.
[0]: https://typst.app/universe/package/merman/
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.