XPath Package for OCaml
- This package implements the full W3C XPath recommendation for the OCaml language; it may work with the output of PXP (XML parser), or with any implementation of the XPath data model.
- http://alain.frisch.fr/soft#xpath

Schematron
- A tree-pattern schema language built on top of XSL with XPath.
- http://xml.ascc.net/resource/schematron/schematron.html

A mini xpath processor
- An XPath processor built for J2ME, suitable for mobile phones.
- http://minixpath.sourceforge.net

Stylus Studio: XPath Tools
- Tools for editing, generating and testing XPath 1.0 and XPath 2.0 expressions.
- http://www.stylusstudio.com/xpath.html

Arbortext: XPath: XML Path Language
- Introduction and tutorial.
- http://www.arbortext.com/html/issue_one.html

W3 Schools XPath
- Tutorial which covers syntax, locations, expressions, functions and examples.
- http://www.w3schools.com/xpath/

DecisionSoft - Pathan
- XPath compliant parsing and evaluation module for the Xerces-C, allows arbitrary selection of nodes from an XML document.
- http://software.decisionsoft.com/

Zvon: XPath Tutorial
- A tutorial with several examples and pictures which can be downloaded for off-line use.
- http://www.zvon.org/xxl/XPathTutorial/General/examples.html

DOM Level 3 XPath Specification
- Provides simple functionalities to access a DOM tree using XPath 1.0. This module builds on top of the Document Object Model Level 3 Core. [W3C Working Draft 31 October 2001]
- http://www.w3.org/TR/DOM-Level-3-XPath/

XML Path Language (XPath) Version 1.0
- Official W3C site describing this language for addressing parts of an XML document which is designed to be used by both XSLT and XPointer. (W3C Recommendation 16 November 1999)
- http://www.w3.org/TR/xpath