According to Wappalyzer 60% of sites that use a JavaScript framework use jQuery: http://wappalyzer.com/categories/javascript-frameworks http://wappalyzer.com/c

According to Wappalyzer 60% of sites that use a JavaScript framework use jQuery: http://wappalyzer.com/categories/javascript-frameworks http://wappalyzer.com/categories/javascript-frameworks It's a different statistic but does make the 50% seem reasonable.