PhiloSURFical is an ontology-based software for browsing a philosophical text, taking advantage of a map of the concepts relevant to the text. The PhiloSURFical application was prototyped with Wittgenstein's Tractatus Logico-Philosophicus and it allows the navigation of a semantically enhanced version of the text.
I developed PhiloSurfical as part of my PhD dissertation at the Knowledge Media Institute, Open University, UK.
By relying on an ontology created to describe the philosophical domain at various levels of abstraction, users can benefit from multiple perspectives on the text and on related resources. For example, they can reorganize the same text according to the relevance of a single topic, e.g. the concept of "logical-independence"; they can query the knowledge base or other repositories in the Semantic Web, such as the DBpedia, by choosing an object of interest (i.e. a philosophical school) and using it to trigger a theoretical learning path, a historical, or a geographical one.
The papers section of this website contains several articles about this work, but mostly, you should look at this article on Synthese for an in-depth discussion of the ontology, and this book chapter for a more e-learning perspective.