Examples of powerful LaTeX packages and techniques in use — a great way to learn LaTeX by example. Search or browse below.

Drawing Feynman Diagrams in LaTeX
The code samples here are taken from the tikz-feynman and feynmf package documentations.
Compile with LuaLaTeX to get the most out of tikz-feynman.
Thorsten Ohl, Joshua Ellis, LianTze Lim

Região sob um gráfico
Neste projeto é apresentado o código para criar uma região colorida sob um gráfico.
Para detalhes sobre o projeto: marcos.ufal.mat@gmail.com
Antônio Marcos Barbosa

Drawing Lewis Structures and Electron Ring Diagrams
The examples are taken from the lewis and bohr package documentations.
LianTze Lim

LaTeX Wine Stains
It was bound to happen. Now besides coffee stains, you can also add wine stains to your LaTeX document!
wine.sty is actually Hanno Rein's coffee4.sty, with all the 'coffee' replaced by 'wine' in the code, and replaced colour definitions.
LianTze Lim

Student report with header
Hiermee kan je aan de slag in Latex. Veel succes!
roeland vervenne

chemische Reaktionsgleichung (Redoxprozesse/Teilgleichungen)
Mit dieser Anleitung können chemische Reaktionsgleichungen produziert werden.
Aus didaktischen Gründen wird u.a. das Package "PSTricks" verwendet, um Pfeile für die Verdeutlichung der Elektronenwandung umzusetzen.
Die Kommandos \anion oder \kation erleichtern außerdem das Einbinden von chemischen Formeln im Fließtext ohne den Code unübersichtlich zu machen.
$\anion{-II}{O}{}{2}$ produziert das Oxid-Anion mit der Oxidationszahl 2...
Achtung: mit "LaTeX dvipdf" kompilieren, sonst werden utf8-Warnungen ausgegeben (Problem bekannt...)
Dr. Markus Woski

Using Dyslexic-Friendly Fonts on Overleaf
The OpenDyslexic and OpenDyslexicAlta fonts are available on Overleaf, which you can use quickly with the fontspec package and XeLaTeX engine.
LianTze Lim (Overleaf)

Template for Tree-Drawing
This is a template that can be used to draw trees for LGCS 105 at Pomona College, using qtree and tree-dvips.
MJKD

Matikkatreeni
Perusanalyysi.
Rodion Efemov