GP is a Windows native app which derives robustness from its Next-Generation level of runtime privacy and settings protection in the live construction of each password candidate. The process of random password generation is to use random numbers to compose a random letter sequence, the password candidate, from sets of source letters (Unicode-compatible). Not all random number generators (RNGs) are the same, but using the same source of randomness for everything isn't how we do it, since some things don't warrant the best.
Everything on a properly maintained and controlled PC is safe from prying eyes, at least since Windows 6 when the server technology Crypt API was brought to the home PC. But, since something intended for security needs to be secured, GP encrypts its settings using the standard Key Storage method of public key cryptography.
GP runs multiple generators concurrently, each equipped with a pair of letter shuffling pools, to provide two layers of randomness to the process— one for the independent character pool supply, and one in the selection between the pair of random candidate letters!
For control over the password production, command line options change the default behavior of the generator either temporarily or for functionality going forward. So, you can use a slot to make a PIN (personal input number) with >gp /su mypin, or >gp /su pin*. Where the setting slot, `mypin', was created with >gp /ss mypin /an—which can be read about inline with, >gp /?, or even, >gp help(that is, any unrecognized gp command). And of course you can read the command info page online, at GP Support.
GP's default password candidate filter eliminates those with letter repetitions, which is for working comfort of the user's letter transposition process (noting or entering). The No Repetitions filter works when the password length is longer than the letter pool size, for example if you're generating a PIN that's longer than 10, the filter will select for minimum repetitions of letters (in this case, digits).