HTML5 validates forms without additional JavaScript. Currently only latest versiones of Firefox, Safari & Google Chrome supports this functionality. This

Tipsy is a jQuery plugin for creating a Facebook-like tooltips effect based on an anchor tag's title attribute.

rainyday.js is a simple script for simulating raindrops falling on a glass surface.   It is a JavaScript library

BlocksIt.js is a jQuery plugin for creating dynamic grid layout. It manages to convert HTML elements into 'blocks' and position

Promo Slide is a jQuery plugin to show content on your site. After scrolling to the bottom of the page, a slide-out panel appears

Tether is a JavaScript library for efficiently making an absolutely positioned element stay next to another

Shuffle, a jQuery shuffle plugin that will categorize, sort, and filter a responsive grid of items.   Shuffle - 

Flow Slider is a JavaScript thumbnail slider. It is customizable, skinnable, fashionable, and looks great on every site. This slider plugin is

jQuery Upvote is a plugin that generates a voting widget like the one used on Stack Exchange sites.  

Barcode Coder is a barcode generation plugin for jQuery.