The Emacs interface is distributed with SICStus and installed by default. The default installation location for the Emacs files is <prefix>/lib/sicstus-4.0.5/emacs/ on UNIX platforms and C:\Program Files\SICStus Prolog 4.0.5\emacs\ under Windows.
For maximum performance the Emacs Lisp files (extension `.el') should be compiled. This, completely optional step, can be done from within Emacs with the command M-x byte-compile-file. See Installation, for further details.
The easiest way to configure the Emacs interface is to load the file sicstus_emacs_init.el from your .emacs file. It will find the SICStus executable and do all initialization needed to use the SICStus Emacs interface.