| authors = MathML 1 was released as a W3C recommendation in April 1998 as the first XML language to be recommended by the W3C. Version 1.01 of the format was released in July 1999 and version 2.0 appeared in February 2001. Implementations of the specification appeared in Amaya 1.1, Mozilla 1.0 and Opera 9.5. In October 2003, the second edition of MathML Version 2.0 was published as the final release by the W3C Math Working Group.
MathML was originally designed before the finalization of XML namespaces. However, it was assigned a namespace immediately after the Namespace Recommendation was completed, and for XML use, the elements should be in the namespace with namespace URL <nowiki>http://www.w3.org/1998/Math/MathML</nowiki>. When MathML is used in HTML (as opposed to XML) this namespace is automatically inferred by the HTML parser and need not be specified in the document.
MathML version 3
Version 3 of the MathML specification was released as a W3C recommendation on 20 October 2010. A recommendation of A MathML for CSS Profile was later released on 7 June 2011; this is a subset of MathML suitable for CSS formatting. Another subset, Strict Content MathML, provides a subset of content MathML with a uniform structure and is designed to be compatible with OpenMath. Other content elements are defined in terms of a transformation to the strict subset. New content elements include which associates bound variables () to expressions, for example a summation index. The new element allows structure sharing. An implementation of MathML 2 landed in WebKit around this same time, with a Chromium implementation following a couple of years later, although that implementation was removed from Chromium after less than a year.
The Second Edition of MathML 3.0 was published as a W3C Recommendation on 10 April 2014. Also in 2015, the MathML Association was founded to support the adoption of the MathML standard. At that time, according to a member of the MathJax team, none of the major browser makers paid any of their developers for any MathML-rendering work; whatever support existed was overwhelmingly the result of unpaid volunteer time/work.
MathML Core
In August 2021, a new specification called MathML Core was published, described as the "core subset of Mathematical Markup Language, or MathML, that is suitable for browser implementation." MathML Core set itself apart from MathML 3.0 by including detailed rendering rules and integration with CSS, automated browser support testing resources, and focusing on a fundamental subset of MathML. An implementation was added to Chromium at the beginning of 2023.