\usepackage{listings}
See also http://www.ctan.org/tex-archive/macros/latex/contrib/listings/listings.pdf
\usepackage{listings} \usepackage{bold-extra} \lstset{ language=PASCAL, basicstyle=\scriptsize, columns= fullflexible } \begin{lstlisting} \end{lstlisting)
For Smalltalk code, use st80.tex. Demo usage: st80demo.tex