It's a pseudo-random number generator.

Err... no. That would be re-inventing the wheel and probably in a bad way.

Entirely. Ventura is an implementation of Fortuna, the PRNG described in Chapter 9 of Cryptography Engineering (2010) by Ferguson, Schneier and Kohno.

Nope. Ventura implements the improvements suggested in How to Eat your Entropy and Have It Too.

Except for one. Entropy can now be provided from remote sources as well. Random bytes from atmospheric, radiation and weather sources are retrieved from REST apis to seed and reseed the generator. Running the PRNG with default local sources is still an option.

Unfortunately it does, those requests take at least 100ms each. However, those are considered the ultimate sources of entropy.