\documentclass[]{article}
\usepackage{lmodern,parskip}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

% For comparison with Euler Script and Ralph Smith's Formal Script
\usepackage[mathscr]{eucal}  % \mathscr with Euler Script
\DeclareSymbolFont{rsfscript}{OMS}{rsfs}{m}{n}
\DeclareSymbolFontAlphabet{\mathrsfs}{rsfscript}

% Now load the package (play with the options):

% \usepackage[mathscr]{pzccal}
\usepackage{pzccal}
% \usepackage[scaled=1.2]{pzccal}

% .......................................................................

\DeclareMathAlphabet{\mathcal}{OT1}{pzcm}{mb}{it}

\begin{document}

\section*{\texttt{pzccal} package test}

The script (calligraphic) math alphabet with Zapf Chancery
(\verb+\mathpzc+):
\[
 \mathpzc{ABCDEFGHIJKLMNOPQRSTUVWXYZ\,
          abcdefghijklmnopqrstuvwxyz\,
          1234567890}
\]
The script (calligraphic) math alphabet with Euler Script
(\verb+\EuScript+):
\[
 \EuScript{ABCDEFGHIJKLMNOPQRSTUVWXYZ\,abc\,123}
\]
The script (calligraphic) math alphabet with Ralph Smith's Formal Script
(\verb+\mathrsfs+):
\[
 \mathrsfs{ABCDEFGHIJKLMNOPQRSTUVWXYZ\,abc\,123}
\]
The script (calligraphic) math alphabet with (\verb+\mathcal+):
\[
 \mathcal{ABCDEFGHIJKLMNOPQRSTUVWXYZ\,abc\,123}
\]
The script (calligraphic) math alphabet with (\verb+\mathscr+):
\[
 \mathscr{ABCDEFGHIJKLMNOPQRSTUVWXYZ\,abc\,123}
\]
Compare script letters (CM, CMcal, pzcm, EuScript, rsfs):
\[
 H \CMcal{H} \mathpzc{H} \EuScript{H} \mathrsfs{H}
 Z \CMcal{Z} \mathpzc{Z} \EuScript{Z} \mathrsfs{Z}
 F \CMcal{F} \mathpzc{F} \EuScript{F} \mathrsfs{F}
\]

Usage examples with \verb+\mathcal+:
\[
 \mathcal{F}\left\{ s(x)\right\} =\int_{-\infty}^{\infty}s(x)
 \mathrm{e}^{\mathrm{i}\omega_{x}x}\,\mathrm{d}{x}
\]

Die Hamiltonfunktion ist die Legendre-Transformierte der Lagrange-Funktion
$\mathcal L(t,q,\dot q)$, die von den generalisierten Koordinaten und
ihren Geschwindigkeiten $\dot q=(\dot q_1,\dot q_2\dots \dot q_n)$ abhängt:
\[
  \mathcal H(t,q,p)= \sum_{k=1}^n \dot q_k\, p_k - \mathcal L(t, q,\dot q)
\]

\makeatother
\end{document}