Plupload is a JavaScript API for dealing with file uploads it supports features like multiple file selection, file type filtering, request chunking, client side image scaling and it uses different runtimes to achieve this such as HTML 5, Silverlight and Flash.
LazyLoad is a lightweight (2.4 kB) and flexible script that speeds up your web application by deferring the loading of your below-the-fold images, videos and iframes to when they will enter the viewport. It's written in plain "vanilla" JavaScript, it leverages the IntersectionObserver API, it supports responsive images, it optimizes your website for slower connections, and can enable native lazy loading.