XEmacs 20.4 Comparison to GNU Emacs


Introduction

Switch from GNU Emacs to XEmacs 20.4

Marc Mengel has informed me that the Computing Division plans to drop support for GNU Emacs and only support XEmacs. If the distinction between these two things eludes you, please read XEmacs -- Emacs: The Next Generation. The FNALU cluster now supports both GNU Emacs 19.34 and XEMacs 20.4. GNU Emacs 20.3 is not supported.

I include here some extracts from mail exchanges with Marc.

I will attempt here to describe the results of my investigations of XEmacs 20.4 on the FNALU cluster. My perspective is that of a GNU Emacs 19.34 user; in particular, I use GNU Emacs with a character cell terminal emulator & don't use X-Windows.


Useful URL regarding differences

The following URL is a useful reference for reading about the difference between the two flavors of Emacsen. It is XEmacs Vs GNUemacs

Extracts from Newsgroups

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Keyboard Mapping Differences

Dired

Miscellaneous

Rmail


Functional Differences/Problems


Problem with Grand Unified Debugger

This problem (inadequacies would be a better terminology) has been described in a posting to Newsgroup "comp.emacs.xemacs". I include it below:
In comparing "gud.el" from our installation of "XEmacs 20.4 "Emerald"
[Lucid] (alpha-dec-osf3.2) of Sat Feb 28 1998 on cobra.pa.dec.com" and
that which comes with GNU Emacs 20.3, I see a number of inadequacies
in the former.  When using M-x dbx to invoke the "dbx" debugger the
source isn't shown in another window (I am invoking XEmacs with the
-nw option, on a character cell terminal (a VT100 emulator)).  This
seems to be because "gud-last-frame" isn't being set inside
"gud-dbx-marker-filter".  It is probably also because
"gud-common-init" doesn't have "marker-filter" as one of its
arguements.

Also, the definition of the "dbx" function has in it the lines:

  (gud-def gud-break  "file \"%d%f\"\nstop at %l"
	   			  "\C-b" "Set breakpoint at current line.")
;;  (gud-def gud-break  "stop at \"%f\":%l"
;;	   			  "\C-b" "Set breakpoint at current line.")

This appears to be a "poor man's" way of dealing with Unix flavors,
since the commented out lines are appropriate for the flavor of Unix
shown above.  The GNU Emacs 20.3 "gud.el" has explicit handling of
Unix flavor dependence.

The "gud.el" that came with GNU Emacs 19.34 didn't have these
inadequacies, as well.

A check of one of the mirror sites for XEmacs indicated to me that
there was no newer version of "gud.el" available.

Was it too much to adapt the "gud.el" from GNU Emacs to XEmacs and
keep the code that dealt with Unix flavor dependences for "dbx"?  I'm
puzzled by this state of affairs.

Differences in Info files


Package Differences

  • The XEmacs maintainers accept packages with fewer constraints than does Richard Stallman for GNU Emacs, so there are more of them included with the XEmacs distribution. For example, the auc-tex package comes with XEmacs. This is a package for working with TeX, La TeX. It is fancier than the built-in "tex-mode". Another example is the "w3" WWW browser, which works within Emacs.

    The presence of these extra packages in the XEmacs distribution probably accounts for the popularity of XEmacs at Fermilab (when compared to GNU Emacs).


    Rmail Differences


    VM for mail


    Comments to: Alan Wehmann(wehmann@fnal.gov)
    Last modified: Wednesday, December 15, 1999