On the Semantic Web, the DARPA agent markup language (DAML) aims to enable the next generation of the web — a web that moves from simply displaying content to one that actually understands the meaning of the content. The DAML program has generated the DAML+OIL markup language. The submission of the DAML+OIL language to the World Wide Web consortium captures the work done by DAML contractors and the EU/U.S. Joint Committee on Markup Languages. This submission was the starting point for the language to be developed by W3C's web ontology working group, WebOnt.

DAML+OIL is a syntax, layered on RDF and XML, that can be used to describe sets of facts making up an ontology. DAML+OIL and its friend OIL (ontology integration language) use RDF namespaces to organize and assist with integration of arbitrarily many different and incompatible ontologies. Current research into DAML is leading toward the expression of ontologies and rules for reasoning and action. Much of the work in DAML has now been incorporated into OWL.