emacstextedit
I'm writing instructions for a project and at some point, for a certain condition one needs to modify a simple plain ascii text file.
For windows I can tell them to fire up notepad. I thought on the mac I could use TextEdit but the TextEdit version I'm using defaults to write rtf, which introduces all rtf symbols in the file which is highly undesirable.
Using emacs or vi from the terminal is not something I want to burden the user with.
What are alternatives?
The format menu has a toggle to switch things for you.
Pressing shift + command + T will toggle the document to plain text mode.
You can also set the default format in the preference pane for the app.
Emacs uses a slightly different setup than e.g. vim. The editor itself can remain active all the time (because you may have it open for other things as well) and you use a utility called emacsclient to connect to it (pass a file to edit) if you need it.
Add the following line to your config file (.emacs):
(server-start) ; Starts server for (among others) emacsclient
Or, if you don't wish to keep the server for emacsclient running at all times, you may issue the command M-x server-start to emacs when you're ready to run. Issuing that command is probably the right thing to do when you're already running emacs, unless you want to reload .emacs.
All you have to do now is to make sure that MUTT uses emacsclient as its editor. You can do this by adding the following line to your config file (.muttrc):
set editor="emacsclient"
Recent versions of mutt (at least 1.4.1) require the following format:
set editor="emacsclient %s"
Source: Emacs and MUTT
set editor="emacs %s"
Best Answer
I would recommend using TextEdit since it is free and the default text editor on OS X.
You only need to learn a key shortcut (Shift-Command-T) to convert the current file to plain text.
Of course other GUI text editors exist on Mac platform but they need to be installed from the App Store or from Internet (see other answers for a selection of the most popular ones).
There is even a setting in TextEdit to let all new documents start as plain text going forward:
Again, this setting is for new documents, so if a document is already open, ⇧⌘T (Format > Make Plain Text) instantly converts a rich text document to plain text.