Sprintf.js
sprintf.js is a complete open source JavaScript sprintf implementation.
Datejs
Datejs is an open-source JavaScript Date Library.
Auto Numeric
autoNumeric is a jQuery plugin that automatically formats currency (money) and numbers as you type on form inputs. It supports most International numeric formats and currency signs including those used in Europe, North and South America, Asia and India (lakhs**).
Yepnope.js
An Asynchronous Conditional Resource Loader
String.js
Extra JavaScript string methods.
CSS3 Pie
A behavior for Internet Explorer allowing it to recognize and render various CSS3 box decoration properties
Store
A better way to use localStorage and sessionStorage
Timezone Js
Timezone-enabled JavaScript Date object. Uses Olson zoneinfo files for timezone data.
Date
Date() for humans
Selectivizr
Selectivizr is a JavaScript utility that emulates CSS3 pseudo-classes and attribute selectors in Internet Explorer 6-8.
Placeholders.js
A JavaScript polyfill for the HTML5 placeholder attribute
Angled Edges
:triangular_ruler: Quickly create angled section edges using only Sass
jQuery Number
Easily format numbers for display use. Replace numbers inline in a document, or return a formatted number for other uses.
Svgeezy
Allows for automatic Image fallbacks for browsers that can't handle SVGs
Flexie
Legacy support for the CSS3 Flexible Box Model
Nerdamer
a symbolic math expression evaluator for javascript
Taggd
A tool to show and add tags to images