Webpack
Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.
Script.js
Asyncronous JavaScript loader and dependency manager
Query Loader2
Version of the QueryLoader by Gaya Design. Preload images with ease.
LABjs
Loading And Blocking JavaScript: On-demand parallel loader for JavaScript with execution order dependencies
RequireJS
A file and module loader for JavaScript
Pilpil
Pilpil - Progressive Image Loading
Blazy
bLazy is a lightweight lazy loading and multi-serving image script. It's written in JavaScript why it doesn't have any dependencies for 3rd party libraries like jQuery. bLazy is working in all modern browser including IE7+.
jQuery Pjax
pushState + ajax = pjax
Oc Lazy Load
Load modules on demand (lazy load) in AngularJS
Lazy Load Xt
Lazy load XT is a jQuery plugin for images, videos and other media
Java Script Load Image
JavaScript Load Image is a library to load images provided as File or Blob objects or via URL. It returns an optionally scaled and/or cropped HTML img or canvas element. It also provides a method to parse image meta data to extract Exif tags and thumbnails and to restore the complete image header after resizing.
Queue
Yet another asynchronous helper library for JavaScript. 387 bytes minified and gzipped!
Aload
Loads images, scripts, styles, iframes, videos and audio asynchronously.
Sea.js
A Module Loader for the Web
Nanobar
Very lightweight progress bars. No jQuery
Px Loader
PxLoader is a simple JavasScript library for creating preloaders and resource downloaders for HTML5 apps.
Lazysizes
High performance and SEO friendly lazy loader for images (responsive and normal), iframes and more, that detects any visibility changes triggered through user interaction, CSS or JavaScript without configuration.