What component of the Architecture Repository holds external reference models, patterns, and reference implementations?

In the context of the Architecture Repository within TOGAF, the component that effectively holds external reference models, patterns, and reference implementations is the Standards Information Base. This repository acts as a collection point for all standards and approved technologies that can be referenced throughout the architecture development process. It serves as a guideline for architects to ensure compliance with external standards and adoption of best practices.

The Standards Information Base also facilitates the alignment of various architectural initiatives and projects with established norms, helping maintain consistency and coherence in architectural practices. By incorporating this type of information, organizations can optimize their architecture processes and enhance the overall quality and effectiveness of their solutions.

In contrast, the other components serve different purposes. The Architecture Landscape provides a high-level view of the various architecture domains and how they relate to each other, the Governance Log maintains records of compliance and audit activities, while the Reference Library contains foundational knowledge and documentation that supports architecture development but may not specifically hold external references to models or standards.