About: http://dbpedia.org/resource/Category:Database_management_systems_by

Property	Value
rdf:type	skos:Concept
rdfs:label	Database management systems by license
skos:broader	dbpedia:Category:Database_management_systems
skos:prefLabel	Database management systems by license
is skos:broader of	dbpedia:Category:Proprietary_database_management_systems dbpedia:Category:Open_source_database_management_systems

About: http://dbpedia.org/resource/Category:Database_management_systems_by_license