Generating system inputs satisfying complex constraints is still a challenge for modern test generators.
We present XMLMate, a search-based test generator specially aimed at XML-based systems. XMLMate
leverages program structure, existing XML Schemas, and XML inputs to generate, mutate, recombine, and
evolve valid XML inputs. Over a set of seven XML-based systems, XMLMate detected 31 new unique failures
in production code, all triggered by system inputs and thus true alarms.