Mathjs
An extensive math library for JavaScript and Node.js
Xdate
A Modern JavaScript Date Library
Sprintf.js
sprintf.js is a complete open source JavaScript sprintf implementation.
jQuery Number
Easily format numbers for display use. Replace numbers inline in a document, or return a formatted number for other uses.
Big.js
A small, fast JavaScript library for arbitrary-precision decimal arithmetic.
Store
A better way to use localStorage and sessionStorage
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**).
Poly
Small, fast, awesome. The only ES5-ish set of polyfills (shims) you can mix-and-match because they're individual AMD modules.
Placeholders.js
A JavaScript polyfill for the HTML5 placeholder attribute
Augment.js
Modern JavaScript in your IE
Timezone Js
Timezone-enabled JavaScript Date object. Uses Olson zoneinfo files for timezone data.
Inversify Js
A powerful and lightweight inversion of control container for JavaScript & Node.js apps powered by TypeScript.
Css3 Finalize
Tired of adding prefix for each broswer when it comes to the new css3 attributes?
Yepnope.js
An Asynchronous Conditional Resource Loader
Nerdamer
a symbolic math expression evaluator for javascript
Typecast.js
Typecast.js :: Solving the simple problems
Svgeezy
Allows for automatic Image fallbacks for browsers that can't handle SVGs