IRPs are the kernel "IPC" mechanism used by NT... And for whole classes of drivers/subsystems IRPs are the core processing mechanism. The IO manager calls to pr

IRPs are the kernel "IPC" mechanism used by NT... And for whole classes of drivers/subsystems IRPs are the core processing mechanism. The IO manager calls to process IRPs could very well be traditional microkernel message passing API's complete with task switching and message copies. While NT is not a microkernel, from a kernel API level it appears to basically be one, only missing the fact that everything is not actually isolated.