Try Meta+x longlines-mode.
That gives you soft wrapping. Note: as of now it's kinda buggy. My experiences is that sometimes if you paste something long, it screws up, or if you call some command that transform the selected region.
I think no softwrap or visual margin is a major usability problem of emacs. I think aquamacs emacs did a great emacs modenization job,
somehow it missed this one.
>> somehow it missed this one. [soft wrap or display margin]
>On Mar 18, 2009 4:20pm, David Reitter
>> Somehow, it didn't miss it.
>LOL. Good. (^_^)
wait, i replied too fast.
Aquamacs emacs actually does not support display margin, which i think is the original poster wanted.
In aquamacs emacs, if you have a long line say 3000 chars, and you turn on “Soft Word Wrap” under “Options”. Then, drag your window to wide, you'll see that the line keeps going from left window border to right window border. That is, there is no right margin.
longlines-mode, effectively introduces right margin. Buggy and the way its done is a hack. Possibly emacs will need to introduce the concept of margins in its display system.
I just looked at XCode. Apparently it doesn't have margin neither. I looked at Eclisp, apparently no. Nor TextWrangler/BBEdit. I wonder if TextMate support it, or MS Visual Studio. (note: all word processors support margins. TextEdit also does if you are in rich text mode.)