The Corvo: Each colony of the Corvo is nominally fairly independent. Communication is slow in Known Space, so a centralised administration would be difficult. If an issue affects more than one such colonies, councils are generated, with independent observers are moderators. The collection of all these interests are colectively refered to as the Corvosphere.
The Iz'kal: All Iz'kal are part of the same network, called The State. The species does have a number of colonies, but these are always considered to be part of the whole. Even with the slowness of Known Space communications, they strive for The Greater Good.
The Raag: The species is split into 4 or 5 major clans and a myriad smaller ones. Each travels around in modified comets and frozen asteroids, called the Ice Fortresses. Periodically, these travel back to their homeworld with resources and information. There is constant warfare between them.
The Humans: No centralised government, considered to be associate race of the Corvosphere.
The Ravagers: Monarchy, insomuch as there are Queens, in the same way of Terran bees or ants. Details are unknown.