The successful deployment of digital technologies by humanities scholars presents computer scientists with a number of unique scientific and technological challenges. The task seems particularly daunting because issues in the humanities are presented in abstract language demanding the kind of subtle interpretation often thought to be beyond the scope of artificial intelligence, and humanities scholars themselves often disagree about the structure of their disciplines. The future of humanities computing depends on having tools for automatically discovering complex semantic relationships among different parts of a corpus. Digital library tools for the humanities will need to be capable of dynamically tracking the introduction of new ideas and interpretations and applying them to older texts in ways that support the needs of scholars and students.This paper describes the design of new algorithms and the adjustment of existing algorithms to support the automated and semiautomated management of domain-rich metadata for an established digital humanities project, the Stanford Encyclopedia of Philosophy. Our approach starts with a "hand-built" formal ontology that is modified and extended by a combination of automated and semiautomated methods, thus becoming a "dynamic ontology". We assess the suitability of current information retrieval and information extraction methods for the task of automatically maintaining the ontology. We describe a novel measure of term-relatedness that appears to be particularly helpful for predicting hierarchical relationships in the ontology. We believe that our project makes a further contribution to information science by being the first to harness the collaboration inherent in a expert-maintained dynamic reference work to the task of maintaining and extending a formal ontology. We place special emphasis on the task of bringing domain expertise to bear on all phases of the development and deployment of the system, from the initial design of the software and ontology to its dynamic use in a fully operational digital reference work.