\section{The graph Simulator} \subsection{Introduction to the Graph Formalism} The first step towards the simulation in the graph formalism has been the discovery of the stabilizer states and stabilizer circuits \cite{gottesman2009}\cite{gottesman1997}. They led to the faster simulation using stabilizer tableaux\cite{gottesman_aaronson2008} and later to the graph formalism . \subsection{Graph Storage} One of the gread advantages of simulating in the graph formalism is a great increase in simulation performance and a lower memory requirement. The simulation of at least $10^6$ qbits on a common desktop computer should be possible\cite{andersbriegel2005}. Therefore one has to take care when choosing a representation of the graph state. The following