Here are the Code examples of this chapter. You can compile them online right on this web page by pressing the Typeset / Compile button. You can also edit them for testing, and compile again.
For a better view with the online compiler, I sometimes use \documentclass[border=10pt]{standalone} instead of \documentclass{article}. Instead of having a big letter/A4 page, the standalone class crops the paper to see just the visible text without an empty rest of a page.
Any question about a code example? Post it on LaTeX.org, I will answer. As forum admin I read every single question there. (profile link).
Using comprehensive font bundles
Latin Modern – a replacement for the standard font
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\begin{document}
\large
\pangram{\rmfamily}
\pangram{\sffamily}
\pangram{\ttfamily}
\pangram{\itshape}
\pangram{\slshape}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Kp-Fonts – another full set of fonts
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{kpfonts}
\begin{document}
\large
\pangram{\rmfamily}
\pangram{\sffamily}
\pangram{\ttfamily}
\pangram{\itshape}
\pangram{\slshape}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Kepler font as light version
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage[light]{kpfonts}
\begin{document}
\large
\pangram{\rmfamily}
\pangram{\sffamily}
\pangram{\ttfamily}
\pangram{\itshape}
\pangram{\slshape}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Times Roman
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{newtxtext}
\usepackage{newtxmath}
\begin{document}
\large
\pangram{\rmfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Palatino
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{newpxtext}
\usepackage{newpxmath}
\begin{document}
\large
\pangram{\rmfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Charter
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage[charter]{mathdesign}
\begin{document}
\large
\pangram{\rmfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

New Century Schoolbook
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{newcent}
\usepackage{fouriernc}
\begin{document}
\large
\pangram{\rmfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Concrete Roman
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{concrete}
\usepackage{concmath}
\begin{document}
\large
\pangram{\rmfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Bookman / Kerkis
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{kmath}
\usepackage{kerkis}
\begin{document}
\large
\pangram{\rmfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Sans-serif fonts
Arev
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{arev}
\begin{document}
\large
\pangram{\sffamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Computer Modern Bright
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{cmbright}
\begin{document}
\large
\pangram{\sffamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Kurier
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage[math]{kurier}
\begin{document}
\large
\pangram{\sffamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Helvetica
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage[scaled=0.95]{helvet}
\usepackage{sfmath}
\begin{document}
\large
\pangram{\sffamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

Typewriter fonts
Courier
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{courier}
\begin{document}
\large
\pangram{\ttfamily}
\end{document}

Inconsolata
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{inconsolata}
\begin{document}
\large
\pangram{\ttfamily}
\end{document}

Bera Mono
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{beramono}
\begin{document}
\large
\pangram{\ttfamily}
\end{document}

Calligraphic fonts
Calligra
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{calligra}
\begin{document}
\large
\pangram{\calligra}
\end{document}

Miama Nueva
\documentclass[preview,border=10pt]{standalone}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage[T1]{fontenc}
\usepackage{miama}
\begin{document}
\large
\pangram{\fmmfamily}
\end{document}

Using arbitrary fonts
The remaining examples can run on Windows computers with the fonts installed, not here on the web site.
Selecting the main font
% !TEX none
\documentclass{article}
\usepackage{fontspec}
\setmainfont{Segoe UI Semilight}
\begin{document}
\large
The quick brown fox jumps over the lazy dog. 1234567890
\end{document}

Selecting multiple font families
% !TEX none
\documentclass{article}
\newcommand{\pangram}[1]{{#1 The quick brown fox jumps over
the lazy dog. 1234567890\par}}
\usepackage{fontspec}
\usepackage{unicode-math}
\setmainfont{Cambria}
\setsansfont{Segoe UI}[Scale=MatchLowercase]
\setmonofont{Lucida Console}[Scale=MatchLowercase]
\setmathfont{Cambria Math}[Scale=MatchLowercase]
\begin{document}
\large
\pangram{\rmfamily}
\pangram{\sffamily}
\pangram{\ttfamily}
\[
\int_a^b \! f(x) \, dx = \lim_{\Delta x \rightarrow 0}
\sum_{i=1}^{n} f(x_i) \,\Delta x_i
\]
\end{document}

This code is available on Github. It is licensed under the MIT License, a short and simple permissive license with conditions only requiring preservation of copyright and license notices.
Go to next chapter.