1) This video shows Mozilla's MathML torture test on macOS.

2) MathML can be rendered with any OpenType MATH font. For example, Latin Modern Math is used here.

3) MathML can be implemented using rules from the TeXBook. The MathML torture test compare your browser rendering (right) against PNG images generated by XeTeX (left).

4) This is MathML rendering in Safari (WebKit web engine). It includes some improvements made by Igalia.

5) This is MathML rendering in Mozilla Firefox (Gecko web engine). Igalia developers have recently contributed to maintenance of the code.

6) MathML is not implemented in Google Chrome (Chromium web engine). Igalia is in discussion with Google to do a LayoutNG-based implementation.

7) Safari exposes information in the accessible tree which can be used by VoiceOver to read mathematical formulaes. This was implemented by Apple developers.

8) Mozilla Firefox exposes the same information for MathML which again can be used by VoiceOver to read mathematical formulaes. This was done thanks to a collaboration between Igalia and Mozilla.

9) Google Chrome currently does not expose any information for MathML which prevents VoiceOver from properly reading mathematical content.