Building on Galen Charlton's investigations into distributed version control systems for metadata management, I was going to offer a prototype system for managing archival finding aids in EAD (Encoded Archival Description). My prototype relied on distributed version control and uses post-commit hooks to initiate indexing and publishing processes. However, I ran into some serious barriers in my implementation, and my talk will focus on the fundamental problem of algorithmically diffing and expressing patches for XML documents. -- Mark A. Matienzo, The New York Public Library