Elliotte Rusty Harold updated the online XLink and XPointer chapters of his best-selling XML Bible. An earlier chapter covers XSL Transformations. He is also the keeper of the Cafe Con Leche XML site.

Mulberry Technologies released references for XPath and XSLT. Mulberry Technologies also offers a quick reference for XML. These quick references were created for their training courses, but are now freely available in PDF format.