jQuery Steps
A powerful jQuery wizard plugin that supports accessibility and HTML5.
Autosize
jQuery plugin for dynamic textarea sizing
Filereader.js
A lightweight wrapper for the JavaScript FileReader interface
Inputex
A javascript framework for YUI to build fields and forms.
H5F
A JavaScript library that allows you to use the HTML5 Forms chapters new field input types, attributes and constraint validation API in non-supporting browsers.
Formvalidation
The best @jquery plugin to validate form fields. Designed to use with Bootstrap + Zurb Foundation + Pure + Semantic UI + UIKit + Your own frameworks. Star it. Try it. Buy it :)
jQuery Autotab
A jQuery plugin that provides auto tabbing and filtering on text fields in a form
Pikaday
A refreshing JavaScript Datepicker — lightweight, no dependencies, modular CSS
Completely
A fresh take on autocompletion for a wonderful user experience
Resumable.js
A JavaScript library for providing multiple simultaneous, stable, fault-tolerant and resumable/restartable uploads via the HTML5 File API.
Formbuilder
[Needs Maintainer] Formbuilder is a small graphical interface for letting users build their own webforms.
Hide Show Password
Because life's too short to waste time re-typing passwords.
Progression.js
A jQuery plugin that gives users real time hints & progress updates as they complete forms
Sisyphus
Gmail-like client-side drafts and bit more. Plugin developed to save html forms data to LocalStorage to restore them after browser crashes, tabs closings and other disasters.
Webuploader
It's a new file uploader solution!
Form
jQuery Form Plugin
At.js
Add Github like mentions autocomplete to your application.