http://uche.ogbuji.net/tech/4Suite/scimitar Scimitar is an implementation of ISO Schematron that compiles a Schematron schema into a Python validator script, making it a faster and somewhat more flexible approach than the usual XSLT implementations. http://www-106.ibm.com/developerworks/edu/x-dw-xschematron-i.html http://www.ascc.net/xml/resource/schematron/schematron.html Schematron is an XML schema language in which you express a set of rules that the document must meet, rather than expressing a full grammar for the XML vocabulary (which is the more common approach to XML schemata). It is by far the most flexible XML schema language available. Scimitar now support all of the draft ISO Schematron specification. It will go through a mostly-bug-fix phase until the 1.0 release. See the TODO file for known gaps in Scimitar functionality and convenience. Scimitar is open source, provided under the 4Suite variant of the Apache license. The compiler program runs standalone on Python 2.2 or more recent, although if you are using an earlier version than 2.3, you must also install Optik 1.4.1 or more recent. In addition to the above requirements the generated validators require 4Suite 1.0a3 or more recent (really only tested with latest 4Suite CVS). -- Uche Ogbuji Fourthought, Inc. http://uche.ogbuji.net http://4Suite.org http://fourthought.com A hands-on introduction to ISO Schematron - http://www-106.ibm.com/developerworks/edu/x-dw-xschematron-i.html Wrestling HTML (using Python) - http://www.xml.com/pub/a/2004/09/08/pyxml.html XML circles the globe - http://www.javareport.com/article.asp?id=9797 Principles of XML design: Considering container elements - http://www-106.ibm.com/developerworks/xml/library/x-contain.html Hacking XML Hacks - http://www-106.ibm.com/developerworks/xml/library/x-think26.html A survey of XML standards - http://www-106.ibm.com/developerworks/xml/library/x-stand4/