Fine Uploader is a multiple file upload plugin with image previews, drag and drop, progress bars. S3 and Azure support, image scaling, form support, chunking, resume, pause, and tons of other features.
It has a plugin-based architecture, first-class support for resumable uploads according to the open standard: tus, and custom encoding backends, making it extensible and robust.
An enhanced HTML 5 file input for Bootstrap 3.x with file preview for various files, offers multiple selection, and more.
The plugin allows you a simple way to setup an advanced file picker/upload control built to work specially with Bootstrap CSS3 styles. It enhances the file input functionality further, by offering support to preview a wide variety of files i.e. images, text, html, video, audio, flash, and objects.
jQuery.filer is a simple HTML5 File Uploader, a plugin tool for jQuery which change completely File Input and make it with multiple file selection, drag&drop support, different validations, thumbnails, icons, instant upload, print-screen upload and many other features and options.
Dropper is a jQuery plugin for simple drag and drop uploads.
JSAjaxFileUploader is a jQuery Plugin with ease of use. Fully customizable with many options. You can have multiple upload forms in a same web page at the same time and user can also select multiple files for upload.
jQuery Upload File plugin provides multiple file uploads with progress bar.Works with any server-side platform (Google App Engine, PHP, Python, Ruby on Rails, Java, etc.) that supports standard HTML form file uploads.
The library is designed to introduce fault-tolerance into the upload of large files through HTTP. It allows for users to pause, resume and even recover uploads without losing state.
Images: crop, resize and auto orientation by EXIF.
Nice tutorial about creating an AJAX file upload form, that will let visitors upload files from their browsers with drag/drop or by selecting them individually.