The document discusses the history and current state of drag and drop functionality on web browsers. It notes that drag and drop was introduced in Firefox 3.6, Chrome 9, and Safari 5 in 2009 and has since been adopted by major websites like Gmail, Mixi, Twitter, Facebook, and Google+. It also provides examples of JavaScript libraries that can be used to implement drag and drop file uploading in HTML5, such as html5uploader, plupload, and a jQuery uploader.