Description

(split from #147)

This focus-area would aim for improving test scores/support for MathML-Core Level 1 in all browsers.

MathML-Core is, itself, a specification about interoperability and providing a platform integrated definition (subset) of MathML to be supported by browsers. This focus area would specifically target the remaining integration gaps (some CSS integrations, for example) for Level 1.

Rationale

Despite its origins, the web has not prioritized the needs of integrating mathematical text into the platform. The situation has been complex for a long time. All browsers supported the integrations done with the HTML parser, and we had 2 implementations (WebKit and Gecko) with very rough edges, strange oddities and some guesswork where things were unclear. MathML-Core provides stricter definition, clarifies and explains platform integration (IDL/CSS, etc). There is an intent to ship in Chromium currently scheduled for release 109 and have been numerous PRs and work in other engines to align. Without good support, authors are left to rely on significantly large JavaScript libraries in order to render mathematical text, or use images. Neither is a solution that we would encourage for any other kind of text, and both disconnect from all of the other text, layout, scripting, accessibility and other integrations of the platform.

While many users will not encounter them in the 'waft and weft' of daily web use, support for it is critical and important. Students online need good math support. Our ability to share so many things is affected - there are millions of math equations in Wikipedia alone.

It is currently the 4th most starred Blink issue (up from 5th not long ago), see https://bugs.chromium.org/p/chromium/issues/list?can=2&q=component:Blink&sort=-stars&colspec=ID%20Stars%20Pri%20Status%20Component%20Opened%20Summary.

It would be ideal to make sure that in 2023 we focus on making this very highly interoperable.

Specification

W3C https://w3c.github.io/mathml-core/
Also a few bits in WHATWG https://html.spec.whatwg.org/
and https://www.w3.org/TR/css-fonts-4/

Tests

https://wpt.fyi/results/mathml?label=master&label=experimental&aligned&view=subtest&q=mathml
(note that at least a small number of these tests are testing things that were dropped from L1)