1. An apparatus that divides roles between a general purpose microprocessor and a first programmable logic device, in making a configuration definition which is loaded into a second programmable logic device to implement a circuit design on the second programmable logic device, the apparatus including: the general purpose microprocessor configured to perform general steps in making the configuration definition which is loaded into the second programmable logic device with programmably configurable interconnections to implement the circuit design on the second programmable logic device with programmably configurable interconnections, wherein the general purpose microprocessor relies on the first programmable logic device to perform particular steps in making the configuration definition; and the first programmable logic device with programmably configurable interconnections, the first programmable logic device coupled to the general purpose microprocessor by a local bus, the first programmable logic device with programmably configurable interconnections configured to perform the particular steps in making the configuration definition more quickly than the general purpose microprocessor, wherein the first programmable logic device performs computations to assist the general microprocessor in making the configuration definition which is loaded into the second programmable logic device, and the first programmable logic device and the second programmable logic device have different configuration definitions.