Description:

MMM Mode is an emacs add-on package providing a minor mode that allows
Multiple Major Modes to coexist in one buffer. It is particularly
well-suited to editing embedded code or code that generates other
code, such as Mason or Embperl server-side Perl code, or HTML output
by CGI scripts.

MMM Mode defines a general syntax--the "submode class"--for telling it
how one major mode should be embedded in another. At present, the list
of supplied submode classes is rather limited, but that will hopefully
change soon. Contributions are always welcome; writing a submode class
can be a good introduction to Emacs Lisp, and is usually a simple
excercise for those already proficient. MMM Mode was originally
designed to work in Emacs 19 and 20 and XEmacs 20 and 21.

This has been created as an emacs-only package as it already exists
for XEmacs in xemacs-packages-extra.