Operating systems kernels are central to the functioning of computers. Security of the overall system, as well as its reliability and responsiveness, depend upon the correct functioning of the kernel. This unique approach - presenting a formal specification of a kernel - starts with basic constructs and develops a set of kernels; proofs are included as part of the text.

The kernel of any operating system is its most critical component, as the rest of the system depends on it. This book shows how the formal specification of kernels can be followed by a completely formal refinement process that leads to the extraction of executable code. This formal refinement process ensures that the code precisely meets the specification. The author documents the complete process, including proofs.

I love virtual machines (VMs) and I have done for a long time.If that makes me "sad" or an "anorak," so be it. I love them because they are so much fun, as well as being so useful. They have an element of original sin (writing assembly programs and being in control of an entire machine), while still being able to claim that one is being a respectable member of the community (being structured, modular, high-level, object-oriented, and so on). They also allow one to design machines of one's own, unencumbered by the restrictions of a starts optimising it for some physical particular processor (at least, until one processor or other). I have been building virtual machines, on and off, since 1980 or there abouts. It has always been something of a hobby for me; it has also turned out to be a technique of great power and applicability. I hope to continue working on them, perhaps on some of the ideas outlined in the last chapter (I certainly want to do some more work with register-based VMs and concur rency). I originally wanted to write the book from a purely semantic viewpoint."

I love virtual machines (VMs) and I have done for a long time.If that makes me "sad" or an "anorak," so be it. I love them because they are so much fun, as well as being so useful. They have an element of original sin (writing assembly programs and being in control of an entire machine), while still being able to claim that one is being a respectable member of the community (being structured, modular, high-level, object-oriented, and so on). They also allow one to design machines of one's own, unencumbered by the restrictions of a starts optimising it for some physical particular processor (at least, until one processor or other). I have been building virtual machines, on and off, since 1980 or there abouts. It has always been something of a hobby for me; it has also turned out to be a technique of great power and applicability. I hope to continue working on them, perhaps on some of the ideas outlined in the last chapter (I certainly want to do some more work with register-based VMs and concur rency). I originally wanted to write the book from a purely semantic viewpoint."

The kernel of any operating system is its most critical component, as the rest of the system depends on it. This book shows how the formal specification of kernels can be followed by a completely formal refinement process that leads to the extraction of executable code. This formal refinement process ensures that the code precisely meets the specification. The author documents the complete process, including proofs.

Operating systems kernels are central to the functioning of computers. Security of the overall system, as well as its reliability and responsiveness, depend upon the correct functioning of the kernel. This unique approach - presenting a formal specification of a kernel - starts with basic constructs and develops a set of kernels; proofs are included as part of the text.

This comprehensive examination of the main approaches to object-oriented language explains key features of the languages in use today. Class-based, prototypes and Actor languages are all examined and compared in terms of their semantic concepts. This book provides a unique overview of the main approaches to object-oriented languages. Exercises of varying length, some of which can be extended into mini-projects are included at the end of each chapter. This book can be used as part of courses on Comparative Programming Languages or Programming Language Semantics at Second or Third Year Undergraduate Level. Some understanding of programming language concepts is required.

Programming in Dylan is aimed at programmers who are already familiar with languages such as Pascal or C but who, as yet, have no knowledge of object-oriented languages. The author takes the reader through the development of Dylan by Apple and introduces the concept of object oriented languages, comparing Dylan to other languages such as CLOS, Smalltalk and C++. The author looks at fundamental concepts of the Dylan language before moving on to present the basic types (Boolean, vectors, strings etc.). Variables, expressions and assignment, and functions (both named and anonymous) are covered in detail. The Dylan class is introduced in its simple form and generic functions and library classes are discussed in depth. The author shows how modularisation needs to be used if large applications are to be developed and illustrates how to construct program libraries. A simulation and modelling example runs through the book.