Vanilla JavaScript Plugin

DragSelect  

Select any DOM element by clicking and/or dragging with your mouse just like you would in a desktop app.

Plugin Website  Demo

Related plugins

dragNdrop  

Easily add drag and drop functionality to DOM elements.

dragula  

Drag and drop so simple it hurts. Sort or move items in a list.

Sizzle JavaScript Selector Library  

A pure-JavaScript CSS selector engine designed to be easily dropped in to a host library. Used and included in jQuery. Rather large in size.