A free CDN (Content Delivery Network) where Javascript developers can host their files.
http://www.jsdelivr.com/
Content Delivery Network
Get access to data on 2,332,725 websites that are jsDelivr Customers. We know of 1,082,128 live websites using jsDelivr and an additional 1,250,597 sites that used jsDelivr historically and 558,323 websites in the United States.
Get a list of 2,332,725 websites using jsDelivr which includes location information, hosting data, contact details, 1,968,143 currently live websites which includes 886,015 domains that redirect to sites in the list. 1,250,597 sites that used this technology previously and 558,323 websites in the United States currently using jsDelivr.