UPDATE:
- Jun 2, 2014:
Remove all the old patched fonts and replace them with the new one.
OSX Mavericks
fontforge installed by homebrew with patch: Homebrew/legacy-homebrew#27221 - Jan 7, 2019: If you're using urxvt add something like this to your ~/.Xresources or ~/.Xdefaults:
URxvt*font: xft:Monaco for Powerline:regular:size=8
URxvt*imFont: xft:Monaco for Powerline:regular:size=8
URxvt*boldFont: xft:Monaco for Powerline:bold:size=8
URxvt*italicFont: xft:Monaco for Powerline:italic:size=8
URxvt*boldItalicFont: xft:Monaco for Powerline:bold:italic:size=8
Make sure to run xrdb -merge ~/.Xresources afterwards and close all urxvt terminals.