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 4,024,393 websites that are jsDelivr Customers. We know of 1,711,742 live websites using jsDelivr and an additional 2,312,651 sites that used jsDelivr historically and 865,060 websites in the United States.
Get a list of 4,024,393 websites using jsDelivr which includes location information, hosting data, contact details, 1,711,742 currently live websites and an additional 978,476 domains that redirect to sites in this list. 2,312,651 sites that used this technology previously and 865,060 websites in the United States currently using jsDelivr.