MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
MarkLogic - Schema-agnostic Enterprise NoSQL database technology, coupled w/ powerful search & flexible application services
Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
BaseX - BaseX is a very light-weight, high-performance and scalable XML Database engine and XPath/XQuery...
SAP HANA - SAP HANA is an in-memory, column-oriented, relational database management system.
Apache Xerces - Advanced XML parser, including support for XML Schema, DOM Level 2, and SAX.