Most of applications on Mac OS X use fixed 72 DPI settings despite of all these Retina and other high-DPI monitors. I understand that this is legacy we’ve got from last century. But c’mon, it is 2014 out there …
Even conventional browsers that supposed to handle scaling well by using CSS rules are failing to render simple things like:
<div style="width:3in; width:3in; border:1px solid"> is it 3 inch square? </div>
you will see everything but not 3 inches square here.
Screenshot is taken on Mac with Dell UltraSharp U2711 monitor.