Computer Associates Erwin
www.cai.com/products/alm/erwin.htm

eXcelon Useful Links
www.eXceloncorp.com/xml_resources/reading_room_links.html#links

Extensible Markup Language (XML)
www.w3.org/XML

MSDN Online XML Developer Center
msdn.microsoft.com/xml/default.asp=xml_pro&catID=687