Altova website: XML Schema Editor
This section provides an overview of how to work with DTDs and XML Schemas. It also describes SchemaAgent and the powerful Find in Schemas feature. In addition to the editing features, XMLSpy provides the following powerful DTD/Schema features:
Support for the OASIS catalog mechanism enables the re-direction of URIs to local addresses, thus facilitating use across multiple workstations.
Components of a large schema can, in Schema View, be created as a separate file. These smaller schema subsets can then be included in the larger schema. The reverse operation, known as flattening a schema, puts the components of included files directly in the larger schema. How to generate schema subsets and flatten schemas is described in the section, Schema Subsets.
A DTD can be converted to an XML Schema and vice versa, and both types of documents can be flattened via commands in the DTD/Schema menu. When a DTD is flattened, components in included/imported modules are saved directly in the parent file, and unused components are deleted.
You can generate, via the DTD/Schema | Generate Sample XML/JSON File menu command, a skeleton XML document based on the active DTD or XML Schema file. This is very useful for quickly creating an XML file based on the active schema.
When the cursor is located within a node in an XML document, clicking the DTD/Schema | Go to Definition menu command opens the schema file and highlights the definition of the selected XML node.