20. the main goal of extensible hypertext markup language (xhtml) is to
XHTML XHTML was developed to make HTML more extensible and increase interoperability with other data formats.[8] In addition, browsers were forgiving of errors in HTML, and most websites were displayed despite technical errors in the markup; XHTML introduced stricter error handling.[9] HTML 4 was ostensibly an application of Standard Generalized Markup Language (SGML); however the specification for SGML was complex, and neither web browsers nor the HTML 4 Recommendation were fully conformant to it.[10] The XML standard, approved in 1998, provided a simpler data format closer in simplicity to HTML 4.[11] By shifting to an XML format, it was hoped HTML would become compatible with common XML tools;[12] servers and proxies would be able to transform content, as necessary, for constrained devices such as mobile phones.[13] By using namespaces, XHTML documents could provide extensibility by including fragments from other XML-based languages such as Scalable Vector Graphics and MathML.[14] Finally, the renewed work would provide an opportunity to divide HTML into reusable components (XHTML Modularization) and clean up untidy parts of the language.[15]