Behave.js
A lightweight, cross browser library for adding IDE style behaviors to plain text areas
Bootstrap Wysiwyg
Tiny bootstrap-compatible WISWYG rich text editor
jQuery.maskedinput
jQuery Masked Input Plugin
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.
Progression.js
A jQuery plugin that gives users real time hints & progress updates as they complete forms
Nod
jQuery plugin that gives you frontend validation for forms.
Completely
A fresh take on autocompletion for a wonderful user experience
Zen Form
Add distraction mode for forms
jQuery Steps
A powerful jQuery wizard plugin that supports accessibility and HTML5.
Starability
Accessible rating forms with cute animations on top.
T Former.js
tFormer.js - Empower your HTML forms
X Sound
XSound gives Web Developers Powerful Audio Features Easily !
Validate.js
Lightweight JavaScript form validation library inspired by CodeIgniter.
X Editable
In-place editing with Twitter Bootstrap, jQuery UI or pure jQuery
Validatr
Cross Browser HTML5 Form Validation.
Inputex
A javascript framework for YUI to build fields and forms.