I have installed it on OS X before. The dev branch had problems installing on OS X, but as of today actually someone put up a dmg that supposedly works (I follow the KiCad dev list).
Gotta say, there are lots of Kicad dmgs out there, but I have yet to see one actually work well. I'm not sure I've even seen one described as working well by the person posting it.
That is the thread I am talking about! Everyone on OS X seemed excited, but I'm not sure that means it is working well yet. I will reply here soon if it is a good installer.
