UMBEL is the Upper Mapping and Binding Exchange Layer, designed to help content interoperate on the Web. UMBEL provides two valuable functions:
First, it is a broad, general reference structure of 34,000 concepts, which provides a scaffolding to link and interoperate other datasets and domain vocabularies. Second, it is a base vocabulary for the construction of other concept-based domain ontologies, also designed for interoperation.
General documentation and search and display functions related to UMBEL are available on UMBEL's main website. From that website, you can easily search and browse the ontology. The UMBEL portal is supported by a rich set of APIs and functionality written in Clojure.