It is an upper ontology of about 28,000 reference concepts, designed to provide common mapping points for relating different ontologies or schema to one another, and
A vocabulary for aiding that ontology mapping, including expressions of likelihood relationships distinct from exact identity or equivalence. This vocabulary is also designed for interoperable domain ontologies.
UMBEL is a class structure used in Linked Data, along with OpenCyc, YAGO, and the DBpedia ontology. Because it is a strict subset of OpenCyc concepts and relationships, mappings to UMBEL can take advantage of the reasoning engines within Cyc.
Including OpenCyc, UMBEL has about 48,000 formal mappings to DBpedia, PROTON, GeoNames, and schema.org, and provides linkages to more than 2 million Wikipedia pages (English version). All of its reference concepts and mappings are organized under a hierarchy of 33 different "super types", which are mostly disjoint from one another. As of version 1.05, UMBEL was split into "core" and "geo" modules (for when the GeoNames mappings are not used).
UMBEL was first released in July 2008. Version 1.00 was released in February 2011. Its current release is version 1.10.