Virtual Machine technology applies the concept of virtualization to an entire machine, circumventing real machine compatibility constraints and hardware resource constraints to enable a higher degree of software portability and flexibility. Virtual machines are rapidly becoming an essential element in computer system design. They provide system security, flexibility, cross-platform compatibility, reliability, and resource efficiency. Designed to solve problems in combining and using major computer system components, virtual machine technologies play a key role in many disciplines, including operating systems, programming languages, and computer architecture. For example, at the process level, virtualizing technologies support dynamic program translation and platform-independent network computing. At the system level, they support multiple operating system environments on the same hardware platform and in servers.

Historically, individual virtual machine techniques have been developed within the specific disciplines that employ them (in some cases they aren't even referred to as "virtual machines”), making it difficult to see their common underlying relationships in a cohesive way. In this text, Smith and Nair take a new approach by examining virtual machines as a unified discipline. Pulling together cross-cutting technologies allows virtual machine implementations to be studied and engineered in a well-structured manner. Topics include instruction set emulation, dynamic program translation and optimization, high level virtual machines (including Java and CLI), and system virtual machines for both single-user systems and servers.

* Examines virtual machine technologies across the disciplines that use them-operating systems, programming languages and computer architecture-defining a new and unified discipline.
* Reviewed by principle researchers at Microsoft, HP, and by other industry research groups.

* Written by two authors who combine several decades of expertise in computer system research and development, both in academia and industry.

虚拟机技术将虚拟化的概念应用于整个机器，规避了真实机器的兼容性限制和硬件资源限制，使软件具有更高的可移植性和灵活性。虚拟机正在迅速成为计算机系统设计中的一个重要元素。它们提供了系统安全性、灵活性、跨平台兼容性、可靠性和资源效率。旨在解决组合和使用主要计算机系统组件的问题，虚拟机技术在许多学科中发挥着关键作用，包括操作系统、编程语言和计算机结构。例如，在过程层面，虚拟化技术支持动态程序翻译和平台独立的网络计算。在系统层面，它们支持在同一硬件平台和服务器中的多个操作系统环境。

从历史上看，各个虚拟机技术都是在采用它们的特定学科中发展起来的（在某些情况下，它们甚至不被称为 "虚拟机"），这使得人们很难以一种连贯的方式看到它们共同的基本关系。在这篇文章中，Smith和Nair采取了一种新的方法，将虚拟机作为一个统一的学科来研究。将跨领域的技术拉到一起，使得虚拟机的实现能够以一种结构良好的方式被研究和设计。主题包括指令集仿真、动态程序翻译和优化、高级虚拟机（包括Java和CLI），以及单用户系统和服务器的系统虚拟机。

*考察了使用虚拟机的各学科的虚拟机技术--操作系统、编程语言和计算机结构--确定了一个新的统一的学科。

* 由微软、惠普的主要研究人员以及其他行业研究小组进行审查。

* 由两位在学术界和工业界拥有数十年计算机系统研究和开发经验的作者共同撰写。