MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
BaseX - BaseX is a very light-weight, high-performance and scalable XML Database engine and XPath/XQuery...
Apache Xerces - Advanced XML parser, including support for XML Schema, DOM Level 2, and SAX.
eXistdb - High-performance native XML database engine and all-in-one solution for application building.
Apache Xalan - XML Databases
Sonic XML Server - Considering Sonic XML Server for your business? Updated for 2020! Access FAQ and important tips before choosing.