MathJax currently interprets the default value for displaystyle on mtable as "inherited" instead of the value "false" specified in the MathML spec. The problem is that this affect the generated MathML output. For example for the markup
{\displaystyle {\begin{aligned}\Gamma (z)&=\int
_{0}^{x}e^{{-t}}t^{{z-1}}\,{\frac {{\mathrm {d}}t}{t}}+\int
_{x}^{\infty }e^{{-t}}t^{{z+1}}\,{\frac {{\mathrm
{d}}t}{t}}\\&=x^{z}e^{{-x}}\sum _{{n=0}}^{\infty }{\frac
{x^{n}}{z(z+1)\cdots (z+n)}}+\int _{x}^{\infty }e^{{-t}}t^{{z}}\,{\frac
{{\mathrm {d}}t}{t}}.\end{aligned}}
on the Fourier Transform page, Mathoid generates <mtable> without explicit displaystyle="true" attribute and so the content render incorrectly in Gecko 29 and (I guess) MathPlayer.
See the discussion in http://lists.w3.org/Archives/Public/www-math/2014Jun/0001.html
An issue is opened in MathJax:
https://github.com/mathjax/MathJax/issues/839
We should cherry-pick the fix when it is ready before Math 2.0.
Version: unspecified
Severity: normal
URL: http://en.wikipedia.beta.wmflabs.org/wiki/User:Physikerwelt/Displaystyle