Extensible Markup Language (XML) has become a standard for data representation and exchange over the Internet. XML schemas are often used to define vocabularies of XML document types and to validate whether the XML documents adhere to the rules defined in the XML schemas. Since XML schemas are textual, programmatic, logical-level schemas, users of XML schemas often find it difficult to understand and communicate with each other the structure and content of the XML schemas and documents as the XML schemas grow in complexity. A solution to the problem would be to convert the logical-level XML schemas developed back to conceptual-level Unified Modeling Language diagrams to facilitate easy understanding and communication. This research paper provides an overview of research on reverse engineering XML schemas into UML diagrams.