\documentclass[11pt]{article}
\usepackage{geometry} 
\geometry{letterpaper}

\usepackage[parfill]{parskip}
\usepackage{graphicx}
\usepackage{amssymb}

\title{Integrating Asymptote and TeXShop for Mac OS X}
\author{Vishaal Rajani \& Cole Zmurchok \\ University of Alberta}
\date{\today}


\begin{document}
\maketitle
\begin{enumerate}
\item Download Asymptote and place the \emph{asymptote-x.xx.src.tgz} file
on the desktop.
\item Open Terminal and type the following. Note that you will
have to enter the root password for the final command. 
\begin{verbatim}
cd Desktop
gunzip asymptote-x.xx.src.tgz
tar -xf asymptote-x.xx.src.tar
cd asymptote-x.xx
./configure
make all
sudo make install
\end{verbatim}
If you get an error at the \verb+./configure+ step, stating that you there
is \verb+no acceptable C+ \verb+compiler found in $PATH+, a solution
is to download and install Xcode here: \\ 
\verb+http://developer.apple.com/TOOLS/Xcode/+.

\item We now create the engine that will typeset Asymptote in TeXShop. The
easiest way to create this engine, which we will
call \emph{asyEngine.engine}, is to navigate
to \verb+~/Library/TeXShop/Engines+ and duplicate one of the
existing \emph{.engine} files. Open the duplicate file and delete the code
there. Type the following:
\begin{verbatim}
#!/bin/sh
location=$(dirname "$1")
basename="${1%.tex}"
#process
cd $location
pdflatex "$1"
asy "${basename}"-*.asy
pdflatex "$1"
\end{verbatim}
Save this file as \emph{asyEngine.engine}.

\item Now we set our engine to be executable. In the terminal, navigate to
the Engines directory and type:

\begin{verbatim}
chmod +x asyEngine.engine
\end{verbatim}

\item Finally, in the terminal, type:

\begin{verbatim}
defaults write TeXShop OtherTeXExtensions -array-add "asy"
\end{verbatim}

This last command allows you choose the \emph{asyEngine} option from the
drop-down menu when you wish to typeset a document that includes asymptote.
\end{enumerate}

Now, if you wish to typeset something simple, like the following red line,
create a new document in TeXShop and type:

\begin{verbatim}
\documentclass[letterpaper,12pt]{article}
\usepackage{amsmath} 
\usepackage{amssymb}
\usepackage{asymptote} 

\begin{document}
\begin{asy}
   size(300);
   draw((0,0)--(1,1),red);
\end{asy}
\end{document}
\end{verbatim}

Choose the \emph{asyEngine} option from the drop-down menu and
press \emph{Typeset}. Your red line will be created in a PDF Document.

On a final note, it is best to avoid using filenames with spaces in them.
For example, avoid filenames such as \verb+asy test.tex+ and instead use
filenames without spaces, such as \verb+asyTest.tex+.

\end{document}