openbsd-src/usr.bin/mg

[This is an edited version of the original mg README, updated slightly to
reflect changes in the last 20 years.]


Mg (mg) is a Public Domain EMACS style editor.  It is "broadly"
compatible with GNU Emacs, the latest creation of Richard M.
Stallman, Chief GNUisance and inventor of Emacs.  GNU Emacs (and other
portions of GNU as they are released) are essentially free, (there are
handling charges for obtaining it) and so is Mg.  You may never have
to learn another editor.  (But probably will, at least long enough to
port Mg...)  Mg was formerly named MicroGnuEmacs, the name change was
done at the request of Richard Stallman.

Mg is not associated with the GNU project, and it does not have the
copyright restrictions present in GNU Emacs.  (However, some modules
do have copyright notices.)  The Mg authors individually may or may
not agree with the opinions expressed by Richard Stallman in "The GNU
Manifesto".

This program is intended to be a small, fast, and portable editor for
people who can't (or don't want to) run real Emacs for one reason
or another.  It is compatible with GNU because there shouldn't be
any reason to learn more than one Emacs flavor.


Beyond the work of Dave Conroy, author of the original public domain
v30, the current version contains the work of:

	blarson@ecla.usc.edu		Bob Larson
	mic@emx.utexas.edu		Mic Kaczmarczik
	mwm@violet.berkeley.edu		Mike Meyer
	sandra@cs.utah.edu		Sandra Loosemore
	mp1u+@andrew.cmu.edu		Michael Portuesi
	RCKG01M@CALSTATE.BITNET		Stephen Walton
	hakanson@mist.cs.orst.edu	Marion Hakanson

People who have worked on previous versions of Mg:

	rtech!daveb@sun.com		Dave Brower

Early release history:

* Nov 16, 1986: First release to mod.sources
* Mar 3, 1987: First Release (mg1a) via comp.sources.unix
* May 26, 1988: Second release: (mg2a) via comp.sources.misc
* Jan 26, 1992: Linux port released by Charles Hedrick. This version
  later makes its way onto tsx-11, Infomagic, and various other Linux
  repositories.
* Feb 25, 2000: First import into the OpenBSD tree, where it is
  currently maintained with contributions from many others.

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Known limitations:

Recursive bindings may cause help and key rebinding code to go into
an infinite loop, aborting with a stack overflow.

Overwrite mode does not work in macros.	 (Characters are inserted
rather than overwriting.)

Dired mode has some problems: .. and . are not recognized as special
cases.  Also, mg uses the output of the command 'ls' to populate a
dired buffer.  This is not ideal, dired mode should probably be
rewritten to use the directory(3) set of functions. 

On systems with 16 bit integers, the kill buffer cannot exceed 32767
bytes.

Unlike GNU Emacs, Mg's minibuffer isn't multi-line aware and hence
some commands like "shell-command-on-region" always pop up a buffer to
display output irrespective of output's size.

While navigating source code using Mg's cscope commands, the cursor
is always at the match location rather than in *cscope* buffer. Mg uses
the same keybindings of GNU Emacs's xcscope package for it's cscope commands.
As Mg's keybindings are case-insensitive some of the commands don't have a
default keybinding.

New implementation oddities:

insert and define-key are new commands corresponding to the mocklisp
functions in GNU Emacs.	 (Mg does not have non-command functions.)
(Mg's insert will only insert one string.)

The display wrap code does not work at all like that of GNU emacs.

Some commands that do not mimic emacs exactly don't have a "standard"
emacs name. For example 'backup-to-home-directory' is only a partial
implementation of emacs' range of commands that allow a user to
customise the backup file location. If a more complete implementation
were coded of these commands the non standard commands would probably
be removed.