Features include drag and drop, and extensive find capabilities on text as well as on XML data.
Abstract Schematron [Schematron] is a structural based validation language, defined by Rick Jelliffe, as an alternative to existing grammar based approaches.
IETF RFC 7303 gives rules for the construction of Internet Media Types for use when sending XML.
XMLFox includes XML View, XML Tree, XML Grid, and XML Script modes for editing.Several schema systems exist to aid in the definition of XML-based languages, while programmers have developed many application programming interfaces (APIs) to aid the processing of XML data. XML-based formats have become the default for many office-productivity tools, including Microsoft Office (Office Open XML), Open and Libre Office (Open Document), and Apple's i Work. Apple has an implementation of a registry based on XML.XML has also provided the base language for communication protocols such as XMPP. XML has come into common use for the interchange of data over the Internet.It can be read from a string, stream, URL, text reader, or a class derived from the Xml Reader.The Load method brings the document into memory and has overloaded methods available to take data from each of the different formats.DTD Elements by Jan Egil Refsnes How to define the elements of an XML document using DTD.