Deprecated in favour of primal.
Extremely simplistic and relatively unoptimised handling of basic tasks around primes:
This uses a basic Sieve of Eratosthenes to enumerate the primes up to some fixed bound (in a relatively memory efficient manner), and then allows this cached information to be used for things like enumerating the primes, and factorisation via trial division.
(Despite the name, it can sieve the primes up to 109 in about 5 seconds.)