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 1,874,694 websites that are Retina JS Customers. We know of 640,171 live websites using Retina JS and an additional 1,234,523 sites that used Retina JS historically and 313,056 websites in the United States.
Get a list of 1,874,694 websites using Retina JS which includes location information, hosting data, contact details, 640,171 currently live websites and an additional 284,262 domains that redirect to sites in this list. 1,234,523 sites that used this technology previously and 313,056 websites in the United States currently using Retina JS.