[Blindmath] Maths on the web (yet again)

Tue Jul 27 16:56:32 UTC 2010

That's a very nice summary, and I agree with everything you say.  I do want
to point to a new technology called "MathJax"  (see mathjax.org).  MathJax
is a Javascript based renderer that will render MathML or a standard subset
of TeX for math  (most people forget that TeX is a powerful programming
language that allows its syntax and the meaning of commands to be changed or
extended).  MathJax has the ability to be configured so that it will pass
MathML or converted TeX to the browser (for Firefox or IE+MathPlayer).  One
great thing about MathJax is the chicken and egg problem is "cracked" (sorry
for the pun) -- MathML can now be rendered on all modern browsers, including
on iphones and ipads!

If you are using IE+MathPlayer and have MathJax configured, then the math is
accessible.  Of course, anytime you convert from one language to another,
there are some assumptions that get made, etc, but MathJax means that even
if you authored your wiki, blog, or general web page with TeX, it can still
be accessible.  To author using MathJax, simply add the approppriate call to
MathJax in the header for the page.  See mathjax.org for details and
examples.

There are some really exciting developments related to MathJax and MathML 3
coming soon.  I'll be blogging about them over the next month or two.  At
the risk of being too self-promoting, I invite everyone to check out the
blog at http://accessiblemath.dessci.com/.

Neil Soiffer
Senior Scientist
Design Science, Inc.
www.dessci.com
~ Makers of MathType, MathFlow, MathPlayer, MathDaisy, Equation Editor ~

On Tue, Jul 27, 2010 at 1:07 AM, Andrew Stacey
<andrew.stacey at math.ntnu.no>wrote:

> There's a new question and answer site starting up focussing on TeX and
> LaTeX.
> As was fairly predictable, one of the first questions is about putting
> maths
> on the web.  Having lurked here for a while, and taken part in the
> discussion
> on Terry Tao's blog a short while ago, I thought I'd try my hand at
> answering
> this question.  However, as I'm neither blind nor an expert on such
> matters,
> there are no doubt things that I've gotten wrong.
>
> Since the website in question is at the moment in a private mode (anyone
> can
> read the questions and answers via
> http://stackmobile.com/site.php?site=tex.stackexchange, but only the
> original
> people who signed up can post stuff), and I've no idea how accessible the
> site
> it, I'm copying my answer below.  I will happily correct any mistakes I may
> have made, or emphasis that I've mislaid, or add anything that members of
> this
> list feel should be said.
>
> The markup language for this is Markdown.  I don't know how email readers
> will
> cope with that so here's a quick explanation of the key points.  Firstly,
> list
> numbering is automatic so all my list entries start with a 1.  Secondly,
> emphasis and bold are done by surrounding the word or text in underscores
> or
> asterisks.  Thirdly, links are done like this: [link text](url).  Fourthly,
> headers are done using hashes.
>
> My answer now follows:
>
> When embedding mathematics into a webpage, there are two primary questions:
>
> 1. What format should be used to display it?
> 1. Where should the conversion be done?
>
> In my opinion, each of these has a definite answer and a different solution
> should only be used if the optimal solution really cannot be done.
>
> 1. **MathML**.  Reasons:
>   1. It is the *only* **accessible** way of doing this.  Putting the
> original LaTeX in an `alt` tag on an image is not accessible - it relies on
> the recipient being able to understand raw LaTeX source code (more on this
> in a moment).  Also, not all of those requiring accessible webpages use
> screen readers, some simply need to enlarge the page.
>   1. It is **styleable** (not sure if that's a word).  Since MathML is part
> of the XHTML suite, it can be styled in the same fashion as the rest of the
> document (namely, via CSS), so the resulting display is far more harmonious
> than any other (try changing the background colour to something easier on
> the eyes at one of those wordpress blogs and you'll see what I mean).
>   1. It is **small**.  A quick test on my system with 515 simple files that
> I happened to have lying around showed that PNGs weighed in at 175kB whilst
> the MathML equivalents were a shade under 60kB.  The PNGs were not large
> resolution, for example the PNG containing the Zeta symbol was a 9x13 image.
>
> 1. **Server-side**.  Reasons:
>   1. It is **small**.  Instead of sending both the source _and_ the
> instructions on how to compile it, you just send the result.
>   1. It is **reliable**.  You can easily check that what you want the
> person to see is what they should see.  In particular, a javascript solution
> relies on two things being correct: the javascript script _and_ the
> implementation of javascript in the browser.  MathML just relies on the
> MathML implementation in the browser.
>   1. It is **fast**.  With server-side caching, you only need to process
> the mathematics once and then it's done.
>   1. It is **verifiable** (similar to reliable, I guess).  I don't fully
> understand the differences between the _types_ of spec that w3c produce, but
> MathML is certainly a recommendation.  Even though browser support is
> variable, the variations are known because they can be measured using the
> open standard, and thus can be taken into account.
>
> Server-side MathML is the optimal solution.  Of course, it's not always
> possible and then other solutions are useful.
>
> There are various standard arguments against using server-side MathML and
> other myths about mathematics in webpages that are worth taking a minute
> over.
>
> ###Myths###
> 1. Sending the raw LaTeX code in an alt tag makes images accessible.
>
>   When people say this, they mean that they can read `$a^2 + b^2 = c^2$`
> and understand it.  Try them on something a little more complicated and
> you'll soon see that this is complete rubbish.  For example, try having
> someone **read out** the following to you:
> `$\begin{array}\ell^0(\mathbb{R})&\;\mapsto&\;\ell^2(\mathbb{R})\\\downarrow&&\uparrow\\L^2(\mathbb{R})&\subseteq\,&L^\infty(\mathbb{R})\end{array}$`.
>  Of course, there's going to be people who will say, "_I_ can understand
> that!" but _that's not the point_.  You write a webpage for other people and
> the more complicated the LaTeX, the fewer the number of people who can
> instantly read it.
>
> 1. MathML is badly supported.
>
>   This is the classic chicken-and-egg.  MathML support is absolutely fine
> in Firefox, in IE with the MathPlayer plugin, and in Amaya (what's that, I
> hear you cry!).  Plus there are groups working on it for Opera and WebKit
> who just _need a little encouragement_!  Sending them an email saying, "I
> love your browser but until it has proper MathML support then I can't use
> it" would provide them with a little more motivation.  Of course, there are
> bugs in the implementations in Firefox and the others, but those are _known_
> and so can be worked around.
>
> 1. MathML requires documents to be valid XHTML.
>
>   Actually, this isn't a myth.  It's absolutely true.  But surely your
> pages were valid to begin with!  I'm a mathematician and my ideal document
> is one that _cannot_ be misunderstood.  That's impossible, so I try for the
> lesser goal of where any misunderstanding can be laid at the door of the
> person reading it rather than me.  MathML, as it's an open standard, allows
> me to reach that goal on webpages - at least technically, the contents are
> more variable!
>
> Finally - on this part - for those that _still_ worry about Joe Blogs (or
> Ola Nordmann, to be geographically correct) not being able to read your
> webpage due to using an old version of IE and refusing to install plugins,
> it is actually possible to have two versions of the mathematics on your
> server and send MathML to those that can see it and PNGs to those that
> can't, thus getting the best of both worlds.
>
> What about implementation?  Well, there you're in luck.  [iTeX](
> http://golem.ph.utexas.edu/~distler/blog/itex2MML.html<http://golem.ph.utexas.edu/%7Edistler/blog/itex2MML.html>)
> can do it all, and in spades.  iTeX is a fast c++ program that converts a
> subset of LaTeX mathematical language into MathML.  The original package
> comes with bindings for ruby, and I've extended this to PHP, Perl, and
> Python.  By combining it with other packages, in particular [svgmath](
> http://grigoriev.ru/svgmath/) or [gtkmathview](
> http://helm.cs.unibo.it/mml-widget/), it is possible to further convert
> the MathML to an image for broken browsers.  (Contact me for these
> extensions; I haven't gotten round to writing them up yet - it's on my TODO
> list!)
>
> For examples, see the [nlab](http://ncatlab.org) (pure MathML) and the
> [nforum](http://www.math.ntnu.no/~stacey/Vanilla/nForum<http://www.math.ntnu.no/%7Estacey/Vanilla/nForum>)
> (MathML, SVG, or PNG depending on what browser you are using).
>
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