In a multiprocessor system, a program's execution that is controlled by controlling an extended process that spans a plurality of processors. The extended process comprises an user process on one processor for executing object code of the program and stub processes each on an individual one of said remaining processors for accessing system resources required for execution of the program. Each stub process gives the extended process access to the resources associated with the processor executing the stub process. Further, a stub process is unique to one particular extended process. Each stub process is interconnected to the user process by an individual virtual communication channel. The virtual communication channels are identified in each process by a port table that is unique to an individual process. When the user process accesses a local file, the access is through a user file table, a system file table, and an inode table. When the user process accesses a remote file, the access is through the port table, over the virtual channel identified from port table to a stub process, and then through the stub process' user file table, system file table, and inode table.