This Linux Journal article by Kamran Husain highlights the basic structure of ODF files, and some internals of the underlying XML files and shows how to use Python to read the contents to perform a simple search for keywords. The code also can be the basis for more advanced operations. In the spirit of openness, open-source software is used to read the ODF files, which in this case are Python and the OpenOffice.org package.

This IBM Developerworks tutorial from Jonathan Levin, shows you how to use OpenOffice's import/export filters
to open your XML data as though it's just a plain document. From there,
users can edit the document much more naturally and then save it back
to its native format. You can also use this feature to easily turn your
documents into XML data.

This article by Erwin Tenhumberg of Sun Microsystems provides a brief introduction to OpenDocument, its history, benefits of use, and available tools.

This monograph was written for those involved in OpenDocument format development, support and promotion and, more generally, for those interested in Open Standards and the Open Source movement, IT professionals and even non-specialised readers. The article was guest edited by Jesús Tramullas-Saz, Piedad Garrido-Picazo and Marco Fioretti.