DAML

From Website: "The DAML language is being developed as an extension to XML and the Resource Description Framework (RDF). The latest release of the language (DAML+OIL) provides a rich set of constructs with which to create ontologies and to markup information so that it is machine readable and understandable."

This is a general-purpose markup language, not specific to marine science. It is included in these references because it serves as an underlying basis for technologies like OWL, a language in which ontologies are often written.