A survey of XML standards

For our NetComputing class we too in the previous period, we had to dive in a lot of webservices and XML stuff. And god, there are many XML API's for many different (and similar) purposes. Now on developerWorks there's a two piece article on different XML standards (because there's more to XML than just the tags): Part 1: XML (the "language" itself), XML Catalogs, XML Namespaces, XML Base, XInclude, XML Infoset, Canonical XML, XPath, XPointer, XLink, Relax NG, W3C XML Schema and Schematron Part 2: XSLT, SAX, DOM, XAPI, XUpdate, XQuery, SQL/XML, CSS, SOAP and WSDL

How many of these did you already know or at least had heard of? ;)