Do small embedded systems need a multitasking operating system? Can’t you just program everything in one big loop? Sure. But have you ever noticed the wait between switching on your DVD player and the first signs of the drive responding to the Play button? We bet that there is no OS inside, just a big loop. It is easy to do better since there exists an OS for even the smallest of microcontrollers.The next question is: do you have to write one yourself?