I'm confused about the way to refer to CMS. It's got a full XPath implementation as well as SloppyDOM (which is inspired by XPath and implements a small subset that should be identical in syntax to XPath for the features it supports) and that's it. There is no other semi-XPath or almost-XPath that's been reduced or crippled since that would obviously be a source of incompatibility when upgrading a Roxen installation.