> OS X supports Emacs key bindings

It's a NextStep thing. You can find the complete list in /System/Library/Frameworks/AppKit.framework/Resources/StandardKeyBinding.dict. You can customize them in ~/Library/KeyBindings/DefaultKeyBinding.dict. The Cocoa API documentation has the details (https://developer.apple.com/library/mac/documentation/Cocoa/...). There's a graphical editor for the DefaultKeyBinding dictionary (http://www.cocoabits.com/KeyBindingsEditor/), but I've never used it.

C-a, C-e, C-n, C-p all work.

EDIT: C-f, C-b work as well.

Are there any others?

Actually, I can tell you for a fact, I've hit M-b (∫) many times and been disappointed by it. I get why, but I'm still disappointed.

Only C-something works, no? I'm also still trying M-b / M-f regularly (with either Option or Command for Meta, which has surprising consequences every single time.)

C-t works though, and that's awesome to correct typos.

Ah, so here's the trick. However I have my modifier keys set up for my external (non-Mac) keyboard means I can't really use them. I use my Caps Lock in Emacs for the C modifier, but in OS X my Alt key is the one that works in normal text inputs.

My favorite one is C-t (transpose)

And of course there's kill C-k and yank C-y

But sadly, no C-w.

I've never used emacs - Is that 'select word'? I have that system-wide by putting

  "^w" = (selectWord:);

into '~/Library/KeyBindings/DefaultKeyBinding.dict'. There's a load of information online about the customisation that can be put in this file. Here's a comment of mine with some links in it: https://news.ycombinator.com/item?id=6718604

Annoyingly, Xcode stopped paying attention to this file at some point around version 4, so now you have to maintain a separate version for that.

It is actually pretty common knowledge that OSX has Emacs keybindings by default for text entry. (At least the basic text editing bindings, don't expect a full Emacs implementation and "M-x tetris".)