CSS Browser Selector

CSS Browser Selector is a very small javascript with just one line which empower CSS selectors. It gives you the ability to write specific CSS code for each operating system and each browser.
More info: http://rafael.adm.br/css_browser_selector

other fork suggestions combined into one new version; now detects:
any version of Firefox
more versions of Windows (Win8, Win7, Vista, XP, Win2k)
more versions of IE under unique conditions
if "no-js" in HTML class: removes and replaces with "js" ()

EXAMPLE

<style type="text/css">
.ie .example {
  background-color: yellow
}
.ie7 .example {
  background-color: orange
}
.gecko .example {
  background-color: gray
}
.win.gecko .example {
  background-color: red
}
.linux.gecko .example {
  background-color: pink
}
.opera .example {
  background-color: green
}
.konqueror .example {
  background-color: blue
}
.webkit .example {
  background-color: black
}
.chrome .example {
  background-color: cyan
}
.example {
  width: 100px;
  height: 100px;
}
.no_js { display: block }
.has_js { display: none }
.js .no_js { display: none }
.js .has_js { display: block }
</style>