cloudhead/less.js — pull request #889 by Harrison (2012-08-10 14:15:30+00:00)
Title: Add dppx and dpcm units to parser dimensions

dppx is currently supported by Firefox >= 16.
This can be used to target retina setups:
@media (min-resolution: 2dppx) {}

http://www.w3.org/TR/css3-values/#resolution
http://www.w3.org/blog/CSS/2012/06/14/unprefix-webkit-device-pixel-ratio/

PS. My editor removed some trailing whitespace in the process.

Cheers