X Editable
In-place editing with Twitter Bootstrap, jQuery UI or pure jQuery
jQuery Timepicker
Adds a timepicker to jQueryUI Datepicker
Form
jQuery Form Plugin
Fancy Input
Makes typing in input fields fun with CSS3 effects
Behave.js
A lightweight, cross browser library for adding IDE style behaviors to plain text areas
Pretty Checkable
A jQuery plugin to replace checkboxes and radios for custom images
Pickadate.js
lightweight jquery date selector with multi-language support
Zen Form
Add distraction mode for forms
Flexi Color Picker
A pure JavaScript color picker - no images, external libraries, CSS or 1px divs.
Parsley.js
Validate your forms, frontend, without writting a single line of javascript!
Zxcvbn
zxcvbn, named after a crappy password, is a JavaScript password strength estimation library. Use it to implement a custom strength bar on a signup form near you!
Garlic.js
Garlic.js allows you to automatically persist your forms' text and select field values locally, until the form is submitted. This way, your users don't lose any precious data if they accidentally close their tab or browser.
Mailcheck
Email domain spelling suggester