To use LispWorks with SLIME it is best to use an image which does not start the LispWorks IDE automatically. You can create such an image with LispWorks Professional or Enterprise Edition. Save it as
~/lw-console
as described in Saving a non-GUI image with multiprocessing enabled.
Configure Emacs to use
"~/lw-console"
as the value of
inferior-lisp-program
as shown in the SLIME README.
LispWorks User Guide and Reference Manual - 21 Dec 2011