JavaScript large number library? [duplicate]

Answer 1

As its author, I recommend big.js, 'a small, fast Javascript library for arbitrary-precision arithmetic with decimal numbers'.

Answer 2

There's a few BigInt implementations out there, for example:

• JavaScript BigInteger Library
• RSA In JavaScript

Layering fixed-point conversion on top of one of them should be pretty easy.

There is also a new decimal type in some implementations, based on a new definition from IEEE 754r — I believe it was part of the (now abandoned) ECMAScript 4 spec, and is carried forward by ECMAScript 3.1/5 and JavaScript 1.9, but I could be wrong on this point.