JQuery Form Validation Plugin.
http://jqueryvalidation.org
JavaScript Libraries and Functions · jQuery Plugin
Get access to data on 8,022,868 websites that are jQuery Validate Customers. We know of 3,919,227 live websites using jQuery Validate and an additional 4,103,641 sites that used jQuery Validate historically and 1,962,953 websites in the United States.
Get a list of 8,022,868 websites using jQuery Validate which includes location information, hosting data, contact details, 3,919,227 currently live websites and an additional 3,764,744 domains that redirect to sites in this list. 4,103,641 sites that used this technology previously and 1,962,953 websites in the United States currently using jQuery Validate.