The following approach should work if you are on Mac OS X, and have the Apple development tools, X11, and Fink installed. Please make sure that you have also a recent version of Emacs.
apt-get install wget gnuplot dx sbcl slime
cd ABSOLUTE_PATH_TO_DIRECTORY_OF_YOUR_CHOICE
# get Femlisp by CVS or FTP
#cvs -z3 -d:ext:anoncvs@savannah.nongnu.org:/cvsroot/femlisp co femlisp
wget -O - http://www.femlisp.org/femlisp-current.tar.gz | tar xzvf -
cd femlisp # change to the Femlisp directory
make configure # interactive setup (choose sbcl)
make femlisp # creates a Femlisp executable
# we are done
make documentation # generate the Femlisp documentation
Now you can continue as described in Emacs configuration.