some tools for diagrams in software documentation
- AsciiFlow Editor online web-editor, limited shapes
- Ditaa Generator Java
- Ascidia Generator Python
yUML (ruby on rails) can be hosted yourself, for 49 USD
- Sequence Diagram - js-sequence-diagrams JavaScript, browser, SVG
- Sequence Diagram - flowchart.js JavaScript, browser, SVG
- KangaModeling, dot-like, web-api-renderer, .NET
Hello, I found this Gist and thought I'd add gravizo. If you're OK with the logo embed, they promise it will always remain free 🙃
So using one of the tools above, if you can get it to export a uml diagram then you can just embed that directly in your markdown doc :)
It takes some tinkering to get the styling, but an interesting option worthy of this excellent list!