jQuery Form Plugin allows you to easily and unobtrusively upgrade HTML forms to use AJAX.
http://jquery.malsup.com/form/
JavaScript Libraries and Functions · jQuery Plugin
Get access to data on 10,979,922 websites that are jQuery Form Customers. We know of 2,261,843 live websites using jQuery Form and an additional 8,718,079 sites that used jQuery Form historically and 970,241 websites in the United States.
Get a list of 10,979,922 websites using jQuery Form which includes location information, hosting data, contact details, 2,261,843 currently live websites and an additional 1,341,093 domains that redirect to sites in this list. 8,718,079 sites that used this technology previously and 970,241 websites in the United States currently using jQuery Form.