mermaid
Markdown-ish syntax for generating flowcharts, mindmaps, sequence diagrams, class diagrams, gantt charts, git graphs and more.
gojs
Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams
@antv/x6
JavaScript diagramming library that uses SVG and HTML for rendering
jssm
A Javascript finite state machine (FSM) with a terse DSL and a simple API. Most FSMs are one-liners. Fast, easy, powerful, well tested, typed with TypeScript, and visualizations. MIT License.