IPC

The mechanisms that let separate programs talk to each other and pass data.

Processes are isolated by design, so when they need to cooperate they use inter-process communication (IPC) — channels like pipes, shared memory, or message passing, often brokered by the kernel. It's foundational to modular systems where, for example, a window compositor talks to applications. In microZeus the mzwm compositor communicates over kernel IPC.