\documentclass{article}
\usepackage{natbib,alifexii_abstract}

\title{This is the Title}
\author{Firstname LastName$^{1}$, FirstName LastName$^{2}$, and FirstName LastName$^{1,2}$\\
\mbox{}\\
$^1$Address of first and third author \\
$^2$Address of second and third author \\
first.corrsponding.author@location.net,
second.corrsponding.author@location.net
}

\begin{document}
\maketitle

\begin{abstract}
Your extended abstract text should go here.
Please adhere to the formatting instructions at \texttt{http://alifexii.org/submissions/}.
The word and pages limits (500 words not including references, two pages max.) are
strict. We encourage one figure per abstract and references -- as e.g. in \cite{ECL96}.
\end{abstract}


\begin{thebibliography}{XXX}
\bibitem[Chu and Adami, 1993]{CHU}
Chu, J. and Adami, C. (1993).
\newblock Propagation of information in populations of self-replicating code.
\newblock In Langton, C. and Shimohara, K., editors, {\em Artificial Life V},
  pages 462--469. MIT Press, Cambridge, MA.

\bibitem[Elena et~al., 1996]{ECL96}
Elena, S., Cooper, V., and Lenski, R. (1996).
\newblock Punctuated evolution caused by selection of rare beneficial
  mutations.
\newblock {\em Science}, 272:1802--1804.
\end{thebibliography}

\end{document}