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 1,849,008 websites that are Retina JS Customers. We know of 568,489 live websites using Retina JS and an additional 1,280,519 sites that used Retina JS historically and 281,506 websites in the United States.
Get a list of 1,849,008 websites using Retina JS which includes location information, hosting data, contact details, 568,489 currently live websites and an additional 267,408 domains that redirect to sites in this list. 1,280,519 sites that used this technology previously and 281,506 websites in the United States currently using Retina JS.