Abstract: A transport mechanism system and method, implemented in software, that permits the coordinated supervision, by an arbitrary number of SUPERVISOR PROGRAMS, of the execution of indirect-addressed interrupt-handling routines in an operating system. The transport mechanism intercepts each call to a supervised interrupt handler, creates a MEMORY MODEL of the then-existing environment, and hands control in sequence to the SUPERVISOR PROGRAMs. Each SUPERVISOR PROGRAM can examine the MEMORY MODEL as well as modify it, and can call a transport mechanism service routine which results in turn in the calling of the normal interrupt-handling routine, but now in the context of the environment specified by the MEMORY MODEL. Such execution is followed by return of control to the calling SUPERVISOR PROGRAM. After all called SUPERVISOR PROGRAMs have completed their execution and returned control to the transport mechanism, the transport mechanism conforms the actual environment to that indicated by the MEMORY MODEL.