While designing XML Schemas it is often useful to be able to see what the resulting XML documents will look like. The XSD Schema diagrams make it clear what the structure is, but it is sometimes easier to see an example of an actual document in order to get a clear picture. The XML Sample generator takes an XSD and generates random sample XML documents based on your XSD. This allows you to quickly see any unexpected artefacts in the XML document.
When tasked with reading an XML document into an application, it is useful to have a good set of valid test cases to work from. In the early stages of a development project such examples can be thin on the ground, so being able to generate them can save hours of manual typing. Furthermore when writing XML from an application, it is useful to have a clear idea of what the XML should look like, samples make it much easier to see where the applications output differ from the test cases.
For reading and writing XML from an application see XML Data Binding.
Testing an application is all about having good test cases, and good test cases need good test data. Being able to generate sample XML documents can save huge amounts of time when creating your test data, as it provides the skeletal message, making easy for meaningful test values to be inserted into the document.