The Neo4j Labs extension plugin called Neosemantics (NSMNTX) helps users work with RDF and linked data by providing an interface to import, export, and manipulate RDF data in Neo4j. It enables users to import RDF data into Neo4j, which can then be queried using Cypher, and also allows for the export of RDF data from Neo4j as a lossless process. NSMNTX provides additional features such as ontology management, model mapping, inferencing, and cloning subgraphs, enabling users to create a more semantic and structured representation of their data in Neo4j. The extension is open-source and can be accessed through the Neo4j Labs page, where documentation, videos, and source code are available for contributors.