Is there an xkeymacs equivalent in Mac?
You could configure some of them in ~/Library/Keybindings/DefaultKeyBinding.dict. See hcs.harvard.edu/~jrus/Site/cocoa-text.html and this sample file: Emacs Opt Bindings.dict.

Another option would be to use KeyRemap4MacBook. It supports over 1000 preconfigured keybindings, including an "Emacs Mode" section.