[aidenn0]

Does it require installing 3rd party software on the host machine?

No, it identifies as a keyboard. It also defaults to generating a password that will use the same scancodes on (most?) western keyboard layouts so that computers configured to default to e.g. QWERTZ or AZERTY will still result in the same password.

[reaperman]

How do you tell it which password to type?

[aidenn0]

IIRC there is a maximum of two; one on short-press and one on long-press.