INFORMATION PROCESSING SYSTEM, METHOD OF PROCESSING INFORMATION, INFORMATION PROCESSING APPARATUS, AND PROGRAM

An information processing system includes at least one information processing apparatus; a receiving unit which receives a first processing request to at least one external service unit performing a process in collaboration with a first program that is operated in the at least information processing apparatus; and a processing request unit which performs, when the first processing request is received by the receiving unit, a second processing request to the at least one external service unit based on the first processing request through an interface unit among a plurality of interface units commonly used for the at least one external service unit, the interface unit being used by the external service unit corresponding to identification information of the at least one external service unit included in the first processing request.