Help:Displaying a formula. MediaWiki uses a subset of AMS-LaTeX markup, a superset of LaTeX markup which is in turn a superset of TeX markup, for mathematical formulae.
It generates PNG images by default. Alternatively the MathJax renderer can be used, this uses a combination of HTML and CSS to display the equation, it can be selected in the user preferences. Although, in all cases mentioned, TeX is generated by compilation, and not by an interpreter program, there is one essential difference between, e.g., Knuth's TeX or Lamport's LaTeX and the present implementation: whereas in the first two cases the compiler typically generates an all-in-one printable output, which has the quality of a whole book with all chapters, sections and subsections, and where no line is "special", in the present case one has, typically, a mixture of TeX images (more precisely: PNG images) for the equations, embedded into usual text, and with short TeX elements usually replaced by HTML parts.
Pauls Online Math Notes. Competence Conference on Social Media - New York - Springer-wiki. StatProb: The Encyclopedia Sponsored by Statistics and Probability Societies.