\chapter{Introduction}\devnote{This chapter is currently being written\ldots}%FIXME: Automation of CMM, FEniCS, purpose of DOLFIN,%FIXME: PSE for differential equations, C++ interface of FEniCS, etc%------------------------------------------------------------------------------\section{The FEniCS project}\index{FEniCS}\index{automation}% FIXME: Automation of CMM, other components of \fenics{}%------------------------------------------------------------------------------\section{The finite element method}\index{finite element method}% FIXME: Automation of discretization%------------------------------------------------------------------------------\section{Overview}\dolfin{} is implemented as a C++ library and can be used either as astand-alone solver, or as a tool for the development andimplementation of new methods. To simplify usage and emphasizestructure, \dolfin{} is organized into three levels of abstraction,referred to as \emph{kernel level}, \emph{module level}, and\emph{user level}, as shown in Figure \ref{fig:components}.  Corefeatures, such as the automatic evaluation of variational forms andadaptive mesh refinement, are implemented as basic tools at kernellevel. At module level, new solvers/modules can be assembled fromthese basic tools and integrated into the system. At user level, amodel of the form is specified and solved, either using one of thebuilt-in solvers/modules or by direct usage of the basic tools.\begin{figure}[htbp]  \begin{center}    \includegraphics[width=12.5cm]{eps/dolfin-components.eps}    \caption{Simplified component diagram of \dolfin{}.}    \label{fig:components}  \end{center}\end{figure}