This book proposes an infrastructure for modeling the architecture of a software system by adapting existing architectural languages, viewpoints and frameworks to domain- and organization-specific features. Under this perspective, the proposed infrastructure allows architects to set up customized architectural frameworks by: (i) defining and choosing a set of viewpoints that adequately fit with the domain and features of the system being developed, (ii) automatically adapting existing architecture description languages to project-specific concerns, (iii) keeping architectural views within the framework synchronized, (iv) enabling consistency and completeness checks based on defined correspondences and rules among architectural elements. The proposed approach builds upon the conceptual foundations of ISO/IEC/IEEE 42010 for architecture description and it is generic with respect to the used architectural elements (i.e., views, viewpoints, languages, stakeholder’s concerns, etc.). The proposed approach is realized through a combination of model transformations, weaving, and megamodeling techniques. The approach has been evaluated in the context of a real complex system.