We are developing an application that involves a substantial amount of XML transformations. We do not have any proper input test data per se, only DTD or XSD files. We\'d li
Liquid XML Studio has an XML Sample Generator wizard which will build sample XML files from an XML Schema. The resulting data seems to comply with the schema (it just can't generate data for regex patterns).
XML-XIG: XML Instance Generator
http://xml-xig.sourceforge.net/
This opensource would be helpful.
For completeness I'll add http://code.google.com/p/jlibs/wiki/XSInstance, which was mentioned in a similar (but Java-specific) question: Any Java "API" to generate Sample XML from XSD?
XML Blueprint also does that; instructions here
http://www.xmlblueprint.com/help/html/topic_170.htm
It's not free, but there's a 10-day free trial; it seems fast and efficient; unfortunately it's Windows only.
There's also http://xsd2xml.com/, an online XSD to XML generator
Microsoft Office has 'InfoPath', which takes an XSD as an import and lets you quickly and easily define a form-based editor for creating XML files. It has two modes - one where you define the form, and another mode where you create the XML file by filling out the form. I believe it first came with Office 2003, and most people never install it. It shocks me at how much I like it.