Decimal.js
An arbitrary-precision Decimal type for JavaScript
Tiny Color
Fast, small color manipulation and conversion for JavaScript
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**).
Mathjs
An extensive math library for JavaScript and Node.js
Inversify Js
A powerful and lightweight inversion of control container for JavaScript & Node.js apps powered by TypeScript.
Nerdamer
a symbolic math expression evaluator for javascript
Poly
Small, fast, awesome. The only ES5-ish set of polyfills (shims) you can mix-and-match because they're individual AMD modules.
Datejs
Datejs is an open-source JavaScript Date Library.
Bignumber.js
A JavaScript library for arbitrary-precision decimal and non-decimal arithmetic
Typecast.js
Typecast.js :: Solving the simple problems
Store
A better way to use localStorage and sessionStorage
Sprintf.js
sprintf.js is a complete open source JavaScript sprintf implementation.
Extract Values
A simple helper to extract values from a string based on a pattern.
Classing Js
Brings the world of classical OOP to javascript
Placeholder Shiv
Tiny polyfill for the placeholder form element attribute. Requires Prototype.js.
Char Funk
a Unicode character utility for JavaScript
Core Lib
A port of the Ruby 1.9.3 corelib to coffeescript/javascript/node that conforms to rubyspec.org.