- Kroki - Online tool and API for many diagramming languages https://kroki.io/
- D2 https://play.d2lang.com/
- https://www.ilograph.com/
- GoJS Web Framework
- Pikchr - simple and generic
- Penrose - complex and generic
- D2 - many use cases
- PlantUML
- GraphViz edotor, viz-js, webgraphviz
- BlockDiag
- Nomnoml (UML)
- C4 PlantUML
- Structurizr
- ? https://drawsql.app/ interactive
- https://dbdiagram.io/ interactive
- interactive https://gojs.net/latest/samples/entityRelationship.html
- https://app.quickdatabasediagrams.com/
- ERD - very simple
- DBML - advanced
- D2 - more general
- Penrose - sets
- ActDiag
- Vega
- Pikchr
- NwDiag
- PacketDiag
- Bytefield
- WaveDrom
- https://xosh.org/text-to-diagram/
- https://github.com/sw-yx/spark-joy/blob/master/README.md#diagramming
- free draw in ASCII Textik, ASCIIflow
- draw block diagrams in fancy handwriting style https://excalidraw.com/
- simple https://flowchart.fun/