Action Keystroke GUI For Mac OS X [duplicate]
Solution 1:
I recommend Keyboard Maestro which lets you set up macros with various actions that can be triggered with keyboard shortcuts or other triggers.
Solution 2:
Check out Hammerspoon. It seems to be very fully featured and — like AutoHotkey — offers a programmatic way to do all sorts of OSX automation, in addition to key binding/remapping.
(It takes a plugin based approach. Karabiner, mentioned in an answer above, can be used as a plugin too allowing its functionality to be enhanced in all sorts of ways.)
http://www.hammerspoon.org/