When you start SXEmacs, it normally attempts to load the file init.el from your .sxemacs directory in your home directory. This file, if it exists, must contain Lisp code. It is called your init file. The command line switches ‘-q’ and ‘-u’ affect the use of the init file; ‘-q’ says not to load an init file, and ‘-u’ says to load a specified user's init file instead of yours. See Entering SXEmacs.
A site may have a default init file, which is the library named
default.el. SXEmacs finds the default.el file through the
standard search path for libraries (see How Programs Do Loading).
The SXEmacs distribution does not come with this file; sites may provide
one for local customizations. If the default init file exists, it is
loaded whenever you start SXEmacs, except in batch mode or if ‘-q’ is
specified. But your own personal init file, if any, is loaded first; if
it sets inhibit-default-init to a non-nil value, then
SXEmacs does not subsequently load the default.el file.
Another file for site-customization is site-start.el. SXEmacs loads this before the user's init file. You can inhibit the loading of this file with the option ‘-no-site-file’.
If there is a great deal of code in your init.el file, you
should move it into another file named something.el,
byte-compile it (see Byte Compilation), and make your init.el
file load the other file using load (see Loading).
See Init File Examples, for examples of how to make various commonly desired customizations in your init.el file.