Drag and drop SVG, HTML or Canvas using mouse or touch input

 Drag-and-drop is a popular and easy-to-learn pointing gesture: move the
 pointer to an object, press and hold to grab it, “drag” the object to a new
 location, and release to “drop”.
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 D3’s drag behavior provides a convenient but
 flexible abstraction for enabling drag-and-drop interaction on selections. For
 example, you can use d3-drag to facilitate interaction with a force-directed
 graph, or a simulation of colliding circles.
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 Node.js is an event-based server-side JavaScript engine.