Copyright © 2014 XPath 3.0 is an expression language that allows the processing of values conforming to the data model defined in [XQuery and XPath Data Model (XDM) 3.0].
The data model provides a tree representation of XML documents as well as atomic values such as integers, strings, and booleans, and sequences that may contain both references to nodes in an XML document and atomic values.
This specification is designed to be referenced normatively from other specifications defining a host language for it; it is not intended to be implemented outside a host language.
The implementability of this specification has been tested in the context of its normative inclusion in host languages defined by the XQuery 3.0 and XSLT 3.0 (expected in 2014) specifications; see the XQuery 3.0 implementation report (and, in the future, the WGs expect that there will also be a — possibly member-only — XSLT 3.0 implementation report) for details.
W3C maintains a public list of any patent disclosures made in connection with the deliverables of the XML Query Working Group and also maintains a public list of any patent disclosures made in connection with the deliverables of the XSL Working Group; those pages also include instructions for disclosing a patent.