LaTeX is an amazing typesetting language that I mostly use to markup various mathematical formulas. I am currently learning more about it and try to use it here in the wiki too with KaTex plugin.

For writing LaTeX I use Sublime Text and LateXTools plugin.

Mathpix - Take a screenshot of math and paste the LaTeX into your editor, all with a single keyboard shortcut.

PlotNeuralNet - LaTeX code for making neural networks diagrams.

Tips and Tricks for Writing Scientific Papers - Best practice and tips & tricks to write scientific papers in LaTeX, with figures generated in Python or Matlab.

Engrafo - Convert LaTeX documents into beautiful responsive web pages using LaTeXML.

LaTeX3 Development Repository - Contains development material for LaTeX3.

Eisvogel - Clean pandoc LaTeX template to convert your markdown files to PDF or LaTeX.

KaTeX - Fastest math typesetting library for the web.

arxiv-latex-cleaner - Easily clean the LaTeX code of your paper to submit to arXiv.

arxiv-style - Latex style and template for paper preprints (based on NIPS style).

Awesome LaTeX drawing - Drawing Bayesian networks, graphical models, and technical frameworks in LaTeX.

BayesNet - TikZ library for drawing Bayesian networks, graphical models and (directed) factor graphs in LaTeX.

LaTeX.Online - Open source service where anyone can build a PDF from GIT repository with TeX files. (Code)

TexLab - Implementation of the Language Server Protocol for LaTeX.

Metropolis - Modern LaTeX Beamer theme.

SwiftLaTeX - WYSIWYG Browser-based LaTeX Editor. (HN)