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 2,011,819 websites that are Retina JS Customers. We know of 654,578 live websites using Retina JS and an additional 1,357,241 sites that used Retina JS historically and 314,882 websites in the United States.
Get a list of 2,011,819 websites using Retina JS which includes location information, hosting data, contact details, 654,578 currently live websites and an additional 269,079 domains that redirect to sites in this list. 1,357,241 sites that used this technology previously and 314,882 websites in the United States currently using Retina JS.