The Extended XQL for Querying and Updating Large XML Databases

XQL has been argued as just a model for asking for specific sets of elements with very limited query capability. This paper proposes several extensions of XQL to address the issues. The extensions include full-text indexed search, path variables, joins, session-based navigations, and updates. Effort has been spent to preserve the conciseness of the language syntax.

http://www.cse.unsw.edu.au/~wong/Papers/exql.pdf