Database management systems are increasingly being called upon to manage XML. The growing amounts of XML data require efficient indexing structures capable of handling the tree-centric nature of XML and processing the path expressions. Furthermore, Web orientation of XML documents and their irregular structure challenge the indexing structures able to handle regular expressions and working in distributed environment. This lecture gives an overview of several recently appeared indexing structures dealing with different aspects of XML data indexing and also introduces the project being developed in Saint-Petersburg, Russia, aiming to support the efficient evaluation of regular expression queries in the network of XML data sources.