Cloudinary
Cloudinary streamlines your web application’s image manipulation needs. Cloudinary's cloud-based servers automate image uploading, resizing, cropping, optimizing, sprite generation and more. Cloudinary's jQuery plugin allows direct uploading from the browser to the cloud and dynamic cloud-based image transformations and effects.
Sebastian Tschan
File Upload widget with multiple file selection, drag&drop support, progress bar, validation and preview images, audio and video for jQuery. Supports cross-domain, chunked and resumable file uploads. Works with any server-side platform (Google App Engine, PHP, Python, Ruby on Rails, Java, etc.) that supports standard HTML form file uploads.
P'unk Avenue
Selective provides multiple selection with autocomplete: a list to which items may be added by typing part of the label. A server-side or client-side source may be specified for autocomplete (see jquery.ui.autocomplete). Items may be reordered if the sortable option is present (this feature requires jQuery UI sortable). Items may also be removed. There are additional features for advanced cases, such as adding options on the fly (for instance, for tagging, or describing attributes of a relationship, like the job title of an employee in a particular department). It is especially useful when there are too many options to be presented in an ordinary dropdown list.
Webshim – polyfills jQuery with many HTML5 features
Alexander Farkas
modular capability-based polyfill loading libary, which extends jQuery with HTML5 features in legacy browsers
Brian Detering
An interface to add and remove a repeatable group of input elements.
jQuery plugin to handle selecting ranges of checkboxes via Shift+Click (and more)
Ravishanker Kusuma
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.
jQuery Mobile – Multiple Month Picker
Leonardo Alkmim
jQuery Mobile plugin for multiple month selection
Sergey Astafev (saxa:p)
jQuery plugin for grabbing GET parameters from url and put, select and check elements of selected form
lou
This is a user-friendlier drop-in replacement for the standard <select> with multiple attribute activated.