Abstract: Over the past decade software architecture has emerged as an important subfield of software engineering. During that time there has been considerable progress in developing the technological and methodological base for treating architectural design as an engineering discipline, including specialized architectural description languages, tools, analytic techniques, handbooks, and methods. In this paper I survey the main features of the field, and then compare software architecture with object-oriented systems to illustrate some of the important similarities and differences between the two fields.