The QUDT, or 'Quantity, Unit, Dimension and Type' collection of ontologies define the base classes properties, and restrictions used for modeling physical quantities, units of measure, and their dimensions in various measurement systems. @en
(2013-07-29) Bernard Vatant: Identified as http://qudt.org/1.1/schema/qudt in the documentation, leading to a different file with the same content. Namespace policy to be clarified.
(2017-01-10) Ghislain Atemezing: Annual review- added v.2, with homepage http://qudt.org/doc/2016/DOC_SCHEMA-QUDT-v2.0.html
(2020-07-23) Ghislain Atemezing: Updated Homepage: http://qudt.org
and Publisher: qudt.org (which is now a legal nonprofit organization) per Steve Ray email (27/07/2020). Also added a new version 2.1.2