num.js will be a Javascript library that will implement various
algorithms in number theory and arithmetic.  It will be meant to be:

- easy to understand;
- asymptotically fast.

It will not be:

- meant for cryptographic applications;
- as fast as a *real* number theory or arithmetic library.

Its planned feature list is:

- arbitrary-precision arithmetic;
- fast primality testing;
- support for Web Workers.