Hello, first of all i think i posted in the wrong section, i am not sure..

Second i am just curious, i know at my skill level i can't accomplish the task, how would you go about creating an OS for e.g. Windows & Mac?

What language is it written in? How do you write it? Where do you write it? Since i would find it strange to create an OS from a program on Windows etc..lol

Would i have the recreate DOS?.. how would it work?