The Nexus-PORTAL-DOORS System (NPDS) is a "who what where" diristry-registry-directory system for identifying, describing, locating and linking things on the internet, web and grid. PORTAL registries identify resources with unique labels and lexical tags in a manner compatible with the lexical web. DOORS directories specify locations and semantic descriptions for these identified resources in a manner compatible with the semantic web. PORTAL registries and DOORS directories were designed to be analogous to IRIS registries and DNS directories. This original design has been enhanced with Nexus diristries to provide integrated services combining the functions of both PORTAL registries and DOORS directories.