JSON Schema is used to validate the structure and data types of a piece of JSON, similar to XML Schema for XML.
This validator checks the markup validity of Web documents in HTML, XHTML, SMIL, Math ML, etc.
Abstract Schematron [Schematron] is a structural based validation language, defined by Rick Jelliffe, as an alternative to existing grammar based approaches.
Tree patterns, defined as XPath expressions, are used to make assertions, and provide user-centred reports about XML documents.
The general intent behind this paper is to furnish the reader with a broad overview of both Schematron and its approach to validation.
The paper completes with some suggestions of possible future extensions.
As an extensible, easy to use, open source tool Schematron is an extremely useful addition to the XML developers toolkit.
The initial section of this paper conducts a brief overview of tree pattern validation, and some of the advantages it has in comparison to a regular grammar approach.
Other tutorial materials fulfill these roles already [Holman],[XPath],[XSLT] ,[Ogbuji C],[Ogbuji U].
During the last few years a number of different XML schema languages have appeared as suggested replacements for the ageing Document Type Definition (DTD).
This instance of the validator is either a development version used for testing purposes, or a local copy of the W3C Markup Validator software used for development and testing purposes.