From the webpage:
BaseX is a very light-weight, high-performance and scalable XML Database engine and XPath/XQuery 3.0 Processor, including full support for the W3C Update and Full Text extensions. An interactive and user-friendly GUI frontend gives you great insight into your XML documents.
To maximize your productivity and workflows, we offer professional support, highly customized software solutions and individual trainings on XML, XQuery and BaseX. Our product itself is completely Open Source (BSD-licensed) and platform independent; join our mailing lists to get regular updates!
But most important: BaseX runs out of the box and is easy to use…
This was a fortunate find. I have some XML work coming up and need to look at the latest offerings.