I expanded the demonic True Name generator. Now you can roll domains of power, spells, and unique physical manifestations for the entities! And I wrote up a Diabolist class (for LotFP) that calls up and binds such demons (they basically act as the spellbook of the summoner).
The project is loosely based on The Lesser Key of Solomon, but instead of the high-level Dukes and Marquises of the demon kingdom it concentrates on the "footsoldiers" and "officers", the ones that a diabolist has a chance to summon AND control. I tried to strike a balance between evocative historical flavor and playability.