ABSTRACT
This chapter describes the step-wise evolution of different design models of operating systems and subsequently their realization from very primitive monolithic systems, then improved hierarchical and extended machines, and later different types of OS based on modular layered structure developed mainly to drive large mainframe machines. A revolutionary concept in the design and development of operating systems for architectural virtual machines is described. Leaving the traditional concept of operating systems by far, a new direction is here portrayed based on the kernel–shell concept used in the design and development of different types of modern operating systems, the first stepping stone of which is the ultimate emergence of famous client–server model. This concept is further fine-tuned in terms of introducing a monolithic kernel, microkernel, and subsequent hybrid kernel. Last, the basic design issues and salient features of generic modern operating systems, including versatile distributed operating systems, are presented here.
