Tex.sx has a tag for questions that is named wiki
and currently has this description:
Topics linked to usage of TeX in wiki-type websites, such as Wikipedia.
Wikipedia (run by Wikimedia, running on Mediawiki software) has long been using mathmode syntax inside <math>
elements for generating formulas in articles. The exact way this has been parsed (client-/server-side MathJax, OCaml texvc, texvcjs, Mathoid) and displayed (source code, MathML, PNG, SVG) has differed over time and may depend on browser capabilities and user settings.
However, it basically supports all of plain LaTeX plus AMSmath.
Since a question of mine about this particular flavor was closed as off-topic: are questions about the MW/WM Tex dialect on topic?
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it doesn't support all of plain LaTeX (looking at your earlier question). – Skillmon Feb 24 '20 at 9:08