[mzl]

Software is deterministic, so it is not really possible to generate noise. There are non-deterministic parts of software (for example, thread interaction in concurrent systems), but this is just observable behavior of hardware effects.

The typical thing people do to get large amounts of randomness is to first generate some "real" random noise from some source (hardware thingamajigs, network timings, user interactions) and extrapolate these into longer sequences of random-looking numbers. The extrapolation can be fast and simple (in which case the randomness is not so good), or it can be slow and complex (to get decent looking randomness).