Polychoron is the potatOS component responsible for multitasking. PotatOS is written in Lua, which uses coroutines for cooperative multithreading, and ComputerCraft, which uses primarily event-driven IO, so Polychoron creates coroutines for every thread/process, waking them when the appropriate event is received. Unlike the native parallel mechanism, Polychoron processes can be added, removed or paused at runtime.
Since PotatOS Epenthesis, Polychoron has also managed capabilities and restrictions for each process and provided IPC.