--- /dev/null
+\chapter{ctsim - the Graphical User Interface}\label{ctsim}\index{ctsim}%
+\setheader{{\it CHAPTER \thechapter}}{}{}{}{}{{\it CHAPTER \thechapter}}%
+\setfooter{\thepage}{}{}{}{}{\thepage}%
+
+\ctsim is the graphical shell for the CTSim project. It is
+written using the wxLibrary for cross-platform compatibility with GTK,
+Motif, and Microsoft Windows. It includes all of the functionality of
+the command-line tool {\tt ctsimtext} as well as image processing and visualization features.
+
+\ctsim can open projection files, image files, phantom definition files, and plotfiles.
+
+\usage
+ctsim [OPTIONS] [files to open...]
+