XHTML + MathML

MathML 2.0 was developed by the W3C Math Working Group and became a Recommendation on 21 February 2001; also adopted the XHTML Modularization Framework

A version of the XHTML DTD extended with the MathML 2.0 module is included in the MathML 2.0 Recommendation

One of the first XHTML Family document types which combined foreign namespace with XHTML