"Currently, embedded systems design often requires building specialized versions of OSes for specific devices - unlike PC or Mid-range computer systems, you can’t just pre-load a generic Windows, Linux or Mac OS, you have to specially tailor the environment to your target device, which could run on a multitude of different embedded chip architectures and use a wide variety of device drivers for system components, such as flash memory chips, network interfaces, display types, et cetera - not to mention run a myriad of different embedded OSes that have to be customized to the device, such as iPhone OS, BlackBerry OS, embedded Linux, Windows CE, vxWorks and Symbian. Just to name a few."
