Osophobia prevailed among programmers. In the early computer system there is notthe concept of operation system. With developing of module technique of software, operation system born the earth. At sometime, early operation system might just bea set of system calls or functions. No matter what a operation system became a hardwareplatform. Application programmers can focus their mind on developing applicationlogics regardless hardware's detail.
In other words, operation system help more and more people join into the group ofdeveloping. At once, application programmers begin to ignore of the technique of hardwareuntil embeded system coming back.
In my eye, what underware is to human body, that operation system is to hardware.
When it comes to operation system, most people can think Windows, MacOS, Linux, FreeBSD,and so forth, at once. They all are hugh operation system. A embeded operation system canbe so small or tiny. For example, GUI is not necessory for a embeded system.
