Line9 - Mermaid rendering engine with its own layout
Show HN: Line9 – A Mermaid rendering engine with its own layout
Line9 is a powerful Mermaid rendering engine that brings its own layout algorithm to the table, offering a fresh approach to diagram creation. With Line9, you can effortlessly transform Mermaid code into beautifully structured diagrams, enhanced by a user-friendly editor and a CLI tool for seamless integration into your workflow. Whether you're a developer documenting architecture or a team collaborating on flowcharts, Line9 delivers crisp, customizable visuals with themes, spacing, and node size controls. Experience the future of diagramming with Line9's innovative rendering technology.
Line9 is not just another renderer—it's a complete reimagining of how Mermaid diagrams come to life, with a layout engine that makes every diagram look its best.
- hankbond
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.
- webslinger1
I have my own flowchart layout code for a video processing application I wrote. But it is mainly to get everything on the page and connected, not to look nice. There is a visual editor for that. But something like this could be useful to me to improve that intial layout. I'll have to look into converting the flow diagram to Mermaid. From what I've seen of Mermaid that is probably not difficult. But I had AI building the Mermaid code in that case. Good work.
- WalterGR
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?
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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.
- sbarre
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
- kannanpoem1984
I have given a try, line9 solve the ui experience of diagram than vanilla mermaid.