An information processing apparatus, an information processing method, an information processing system, and an information processing program are provided. The present invention can execute distributed processing effectively with certainty among different information processing apparatus connected through a common network. Each of first to fourth information processing apparatus includes a main processor and sub processors. When sub processor programs are to be executed by sub processors in response to an operation of a user, the first apparatus secures a necessary number of free sub processors if this is determined possible. If the necessary number of free sub processors are not available, then the first apparatus successively issues a request to secure sub processors to the other apparatus. If the necessary number of sub processors cannot be secured from among free sub processors in the entire network, those sub processors which are executing sub processor programs having a lower priority are secured for execution of the sub processor programs.