XSDB XML is to DATA as HTML is to DOCUMENT. Publish and combine data as easily as HTML format and web browsers publish and view documents. Implementations in Python, javascript, java, C#/.NET.
XQuench is an XML Query parser and engine. The aim is to provide programmers with an API that implements the specifications at http://www.w3.org/XML/Query At first, XQuench will be Java-only. Future versions will include C++, while keeping a similar API.