Semantic Web for Earth and Environmental Terminology (SWEET) are a suite of 200 ontologies covering over 6000 concepts.
CMO, the chemical methods ontology, describes methods used to collect data, prepare and separate material, synthesise materials, and the instruments used in these experiments, such as mass spectrometers and chromatography columns. (complement to OBI)
ChEBI is a large ontology focused on the chemicals applicable to biological processes.
The Ontology for Biomedical Investigations (OBI) project is developing an integrated ontology for the description of life-science and clinical investigations. (complement to CMO)
The BioAssay Ontology (BAO) describes biological screening assays and their results including high-throughput screening (HTS) data for the purpose of categorizing assays and data analysis.
The Chemical Information Ontology (CHEMINF) aims to establish a standard in representing chemical information. In particular, it aims to produce an ontology to represent chemical structure and to richly describe chemical properties, whether intrinsic or computed.
The Library of Congress Subject Headings (LCSH) comprise a thesaurus (in the information science sense, a controlled vocabulary) of subject headings, maintained by the United States Library of Congress, for use in bibliographic records.
The Ontology of Units of Measurement is developed as part of the OBO Foundry initiative.
The QUDT Ontologies, and derived XML Vocabularies, are being developed by TopQuadrant and NASA