mxGraph - mxGraph is a fully client side JavaScript diagramming library - jgraph/mxgraph
GoJS - GoJS is a JavaScript library for building interactive diagrams on HTML web pages. Build apps with flowcharts, org charts, BPMN, UML, modeling, and other visual graph types.
Diagram-JS - JavaScript toolbox for displaying and modifying diagrams on the web.
FabricJS - Fabric.js is a powerful and simple Javascript HTML5 canvas library,
jsPlumb - jsPlumb is an advanced, standards-compliant and easy to use JS library for building connectivity based applications, such as flowcharts, process flow diagrams, sequence diagrams, organisation charts, etc. More than just a diagram library.
JavaScript InfoVis Toolkit - Interactive Data Visualization Library for the Web