Starting from January 2023, Google Chrome and Microsoft Edge are now supporting the encoding and display of MathML. This change is due to Igalia bringing back the support for MathML to Chromium, the open-source core of the two browsers.

This is an important change for the digital publishing industry too, since EPUB reading systems are based on webviews. In this way, many reading solutions will soon be able to natively support fully accessible mathematical formulas, without the need for additional plugins.

What is MathML?

MathML (Mathematical Markup Language) is an XML-based language that describes mathematical and scientific notations in web content. Released as a recommendation in April 1998, it is now in its third version (MathML Version 3.0), but the version 4.0 is already under development (see the W3C First Public Working Draft, released in September 2022).

Despite its long history, support by browsers has been quite inconsistent over time. But now, an implementation of the MathML Core specification (a subset with increased implementation details tailored for browsers and designed specifically to operate with the Open Web Standards) is in the releases of Chrome and Edge, making it enabled by default for all users.

Accessible Math

The subject of mathematics in web pages is a topic that goes back to the dawn of the Web itself. The need was to introduce and support mathematical and scientific notations in an appropriate way.

Now, almost thirty years later, the use of a markup language such as MathML for encoding mathematical formulae is also proving to be crucial in terms of accessibility. Using MathML means giving the different components of the formula a precise semantic meaning that can be interpreted by Assistive Technologies and conveyed to their users.

The recent pandemic has made it clear how important it is to have accessible digital educational content: students from all around the world have been forced to attend virtual classes, to take tests and exams remotely, to study on digital books.

In most cases, mathematical formulae are entered as images and are therefore not accessible to blind users unless they are accurately described by an alternative text, but they are also problematic for low vision and print impaired users: images of text are difficult to enlarge and do not follow user settings to change the background or the text color, nor it is possible to change the font for better readability.

Since the support for MathML has been variable for many years across different platforms, publishers of scientific materials had to provide fallback solutions, while reading systems often had to rely on polyfill (downloadable services needed to support features not implemented in the browser) to support it.

Now that browsers natively support MathML, the digital publishing industry will be able to consider EPUB format for their scientific ebooks.