ddemaree

@mixin retina($ratio: 1.5) {
  $dpi: $ratio * 96;
  $opera-ratio: $ratio * 100;

  @media only screen and (-webkit-min-device-pixel-ratio: #{$ratio}),
         only screen and (     -o-min-device-pixel-ratio: '#{$opera-ratio}/100'),
         only screen and (                min-resolution: #{$dpi}dpi),
         only screen and (                min-resolution: #{$ratio}dppx) {
    @content;
  }

jonkemp

History of Frontend Tooling

http://ln.hixie.ch/?start=1037910467&count=1

http://ln.hixie.ch/?start=1137740632&count=1

http://software.hixie.ch/utilities/js/live-dom-viewer/

http://joehewitt.com/2006/03/26/firebug-03-preview