Booch, GradyGimnich, RainerKaiser, UweQuante, JochenWinter, Andreas2019-04-042019-04-0420083-88579-220-8https://dl.gi.de/handle/20.500.12116/21649Software is invisible to most of the world. Although individuals, organizations, and nations rely on a multitude of software-intensive systems every day, most software lives in the interstitial spaces of society, hidden from view except insofar as it does something tangible or useful. Furthermore, most interesting software is continuously evolving: it is never turned off, but rather is adapted, integrated, extended, and reused. As such, while greenfield software development persists, most software development is brownfield, requiring teams to conduct archeological digs in order to understand, reason about, and transmogrify those systems. It is a sign of maturity for any given engineering discipline when we can name, study, and apply the patterns relevant to that domain. In civil engineering, one can study the fundamental elements of architecture in works that expose and compare common architectural styles. Similarly, in chemical engineering, mechanical engineering, electrical engineering, and now even genomic engineering, there exist libraries of common patterns that have proven themselves useful in practice. Unfortunately, no such architectural reference yet exists for software-intensive systems. Although the patterns community has pioneered the vocabulary of design patterns through the work of the Hillside Group and the Gang of Four (in their seminal book, Design Patterns), our industry has no parallel to the architecture handbooks found in more mature design disciplines. The primary goal of the Handbook of Software Architecture (http://www.booch.com/architecture) is to fill this void in software engineering by codifying the architecture of a large collection of interesting software-intensive systems, presenting them in a manner that exposes their essential pattern and that permits comparisons across domains and architectural styles. In this presentation, we will examine the nature of software archeology and some of the systems under study in the Handbook.enText/Conference Paper1617-5468