Retina.js is an open source script that makes it easy to serve high-resolution images to devices with retina displays.
http://retinajs.com/
JavaScript Libraries and Functions · Media
Get access to data on 1,934,789 websites that are Retina JS Customers. We know of 670,153 live websites using Retina JS and an additional 1,264,636 sites that used Retina JS historically and 329,098 websites in the United States.
Get a list of 1,934,789 websites using Retina JS which includes location information, hosting data, contact details, 670,153 currently live websites and an additional 266,105 domains that redirect to sites in this list. 1,264,636 sites that used this technology previously and 329,098 websites in the United States currently using Retina JS.