OpenType Math Tables

The math tables created for the math facility in Word 2007 and other Microsoft Office applications are now officially part of the OpenType standard ISO/IEC CD 14496-22 3rd edition. See Section 6.3.6 MATH. You can download a copy of the whole standard from here. We always hoped that the tables would become part of the official OpenType standard so as to encourage people to create math fonts with the power and elegance of the Cambria Math font which ships with Windows. I’ve been sending the math-table specification to anyone who asked for several years now, but it’s considerably better to have the standard available publically. A bonus is that the prose has been improved and enhanced. Enjoy!

The OpenType math tables were designed to enable programs to reproduce the elegant math typography of TeX. In addition they provide special features such as data to kern the spacing between the base of a subscript or superscript and the script itself. The tables were included in Cambria Math when it first shipped in 2007.

They are also included in a version of the STIX fonts known as XITS - OpenType MATH enhanced STIX fonts. The STIX fonts are based on the Times Roman typeface. XITS is a right-to-left spelling of STIX and the XITS author hopes to extend XITS to support right-to-left math. Right-to-left math can be represented in MathML 3.0 and is described in this post. In particular, right-to-left support implies inclusion of mirrored variants (OpenType rtlm tag) for many operators such as integrals and summations as well as glyphs for the Arabic math alphabetics (see the Unicode Standard’s U+1EE00..U+1EEFF).

An interesting post is, which illustrates how FontForge can let you look at the font math tables, among other things.

Another exciting development is that Firefox now displays MathML using some of the OpenType math tables. Check out this link to see how your browser fares in a MathML torture test compared to TeX. Firefox looks really very good. Internet Explorer uses LineServices, the component that Office apps call to layout math zones with the help of the tables to achieve TeX typographic quality. But since IE doesn’t currently enable the LineServices math handler, the math it displays in the MathML torture test doesn't resemble math. Hopefully that will change.

Comments (5)
  1. L. says:

    It's nice to see your work being used in so many places.  Once again, thank you very much.

    Regarding math in IE, indeed, it would be nice to see it use LineServices' math rendering.  However, shows that MathML is "Not currently planned", not even "Under consideration".

  2. Frédéric Wang says:

    That's great to see that the MATH table will finally be part of an open standard. I hope font designers and implementers will be able to use it! More info:

    * The initial Open Type MATH support is only for Gecko 31, which will be released at the end of July (but one can try pre-release builds of course)

    * At the moment only some partial support has landed (essentially the MathVariant table + the ssty feature + MinOperatorHeight)… I have pending patches for other MATH features (…/MozillaCentralPatches) and hopefully, I'll find time to continue the work.

    * The parsing of the MATH table has landed in WebKit too. However, the MathML rendering does not use that table yet. I have pending patches (…/WebKitPatches) that I hope will be merged too. They essentially add support for part of the MathVariant table + MinOperatorHeight + the radical constants. I published a screenshot here some time ago:…/screenshots-31369

    I'm looking forward to seeing MathML support in IE… Microsoft Office has good math support, let's put it in the browser too!

  3. Robert says:

    > were designed to enable programs to reproduce the elegant math typography of TeX

    I hope they will do better! Despite its many niceties, TeX fails to get the spacing right in simple expressions like

    it For all $Y$ and $W$ containing …

    Unfortunately, because it’s too much trouble to fix this by hand all the time, this quirk (among others) remains clearly visible in practically all professional publications that use LaTeX to typeset theorems.

  4. Carlos Araya says:

    If I save an equation to html, will it save equations as images or as MathML (which the IE team has no plans to support)?

  5. MurrayS3 says:

    It saves them as OMML (Office MathML, a different XML from MathML) in comments and also as pngs for use by browsers.

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