Index: trunk/doc/pslib/psLibSDRS.tex
===================================================================
--- trunk/doc/pslib/psLibSDRS.tex	(revision 404)
+++ trunk/doc/pslib/psLibSDRS.tex	(revision 408)
@@ -1,3 +1,3 @@
-%%% $Id: psLibSDRS.tex,v 1.34 2004-04-08 23:22:10 price Exp $
+%%% $Id: psLibSDRS.tex,v 1.35 2004-04-09 01:29:44 price Exp $
 \documentclass[panstarrs]{panstarrs}
 
@@ -99,5 +99,31 @@
 is called \code{psImageCopy()}.
 
-\tbd{discuss the use of external libraries (list them)}
+\subsection{External Libraries}
+
+It is anticipated that many of the functions specified in this
+document will be implemented through wrapping external libraries:
+\begin{itemize}
+\item Many of the matrix functions, some of the polynomial and
+minimisation functions functions will wrap the GNU Scientific Library
+(GSL; \href{www.gnu.org/software/gsl/}{\tt www.gnu.org/software/gsl});
+\item The sort functions will wrap the system \code{qsort} call;
+\item Some of the Fourier transform functions will wrap the Fastest Fourier
+Transform in the West library (FFTW; \href{www.fftw.org}{\tt www.fftw.org});
+\item The FITS functions will wrap the CFITSIO library
+(\href{heasarc.gsfc.nasa.gov/docs/software/fitsio/}{\tt
+heasarc.gsfc.nasa.gov/docs/software/fitsio/}); and
+\item Many of the astronomy routines will wrap the StarLink Astronomy
+libraries (SLALib;
+\href{star-www.rl.ac.uk/star/docs/sun67.htx/sun67.html}{\tt
+star-www.rl.ac.uk/star/docs/sun67.htx/sun67.html}.
+\end{itemize}
+
+In addition, some of the functions were implemented in a limited
+fashion in the Pilot Project.  Also, RHL has provided functional
+prototype code for the memory management, tracing and message logging
+functions (some of which need to be revised), and the data containers
+(doubly-linked lists, hashes, arrays).
+
+\subsection{Threads}
 
 \tbd{discussion of thread safe?}