Structured DynamicsUMBEL is a lightweight reference ontology that aimed to serve as a common scaffolding for linking and interoperating datasets and domain vocabularies across the semantic web. Developed by Mike Bergman and Frederick Giasson at Structured Dynamics, UMBEL provided a broad concept structure of approximately 34,000 concepts organized through SKOS and OWL. Although the project is no longer actively maintained, its files remain available in a GitHub archive.
Background
UMBEL was first developed around 2008, emerging from the recognition that the rapidly growing linked data ecosystem needed a shared upper-level concept structure to facilitate interoperability between disparate ontologies and datasets. Rather than attempting to create a comprehensive upper ontology from scratch, UMBEL was derived from OpenCyc, selecting and reorganizing a subset of its concepts into a more accessible and web-friendly structure.
The project was developed by Structured Dynamics, a small company specializing in semantic web technologies. Mike Bergman, who had written extensively about the need for concept-level interoperability on the web, led the conceptual design, while Frederick Giasson handled much of the technical implementation. Development progressed through several versions, with version 1.50 being the final release.
Purpose & Scope
UMBEL served two complementary purposes:
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Reference structure -- a broad, general concept graph of 34,000 concepts providing scaffolding for linking other datasets and domain vocabularies. By mapping domain-specific terms to UMBEL concepts, different datasets could be related to each other through a shared conceptual backbone.
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Base vocabulary -- a foundation for constructing domain-specific concept ontologies that were themselves designed for interoperation. UMBEL concepts could be extended and specialized for particular domains while retaining connections to the broader reference structure.
Technical Structure
UMBEL was organized into several components, reflected in the GitHub repository structure:
- Ontology -- the core UMBEL ontology defining the concept classes and their relationships
- Reference Structure -- the 34,000-concept reference graph with SKOS hierarchical and associative relationships
- Typologies -- classification structures for different categories of entities
- External Ontologies -- mappings and alignments to other well-known ontologies
- Documentation -- guides and reference materials
The ontology used standard semantic web serializations including RDF/XML, Turtle, and N-Triples. Concepts were organized using SKOS (Simple Knowledge Organization System) broader/narrower relationships, with OWL class definitions providing formal ontological structure.
Governance & Maintenance
UMBEL was maintained by Structured Dynamics as an open-source project. The GitHub repository shows 58 commits from 3 contributors across 3 tagged releases. The project is no longer under active development. The original umbel.org website, which hosted extensive documentation, browsable concept trees, and API access, is no longer online. The GitHub repository serves as the surviving archive of the project's ontology files and documentation.
Notable Implementations
During its active period, UMBEL was used by several linked data projects and platforms:
- OpenStructs -- Structured Dynamics' semantic web framework used UMBEL as its default concept structure
- Various linked data projects -- used UMBEL mappings to facilitate cross-dataset queries
- Research projects -- academic work on ontology alignment and concept-level interoperability referenced UMBEL
Related Standards
- SKOS (Simple Knowledge Organization System) -- UMBEL used SKOS for concept organization
- OWL (Web Ontology Language) -- formal class definitions in UMBEL
- OpenCyc -- the source from which UMBEL concepts were originally derived
- DBpedia -- UMBEL provided mappings to DBpedia concepts