In the field of software architecture, there has been a paradigm shift from describing the outcome of the architecting process to documenting architectural knowledge, such as design decisions and rationale. Moreover, in a global, distributed setting, software architecting is essentially a collaborative process in which sharing and reusing architectural knowledge is a crucial and indispensible part. Although the importance of architectural knowledge has been recognized for a considerable period of time, there is still no systematic process emphasizing the use of architectural knowledge in a collaborative context. In this chapter, we present a two-part solution to this problem: a collaborative architecting process based on architectural knowl...