An XML parser parses the XML document to check well-formedness. All XML parsers check well-formedness and some XML parsers are also validating parsers. Validating XML parsers also check whether the document is a valid XML document by comparing the document to a document type definition (DTD). Be sure you use a validating XML parser if you are checking valid XML documents.

The VA Smalltalk parser can be invoked either as a validating parser or as a non-validating parser.

If your document does not conform with XML rules or your DTD, it may not be read properly by an XML reader. You can create valid XML documents in validating XML editors, which are designed to avoid errors and often don't allow them. XML Parsers can help you find the reason why XML documents are not being read properly. You can also use them to check your documents as you are creating them.

For useful XML tools, see IBM's XML web site at http://www.ibm.com/developerworks/xml/