Double Vision – Give the Browsers CSS They Can Digest

When surfing the Web, one might encounter websites that look completely different in Microsoft Internet Explorer and Firefox/Opera. We don’t mean websites with bugs, or ones that were developed for MSIE only. We’re talking about websites deliberately showing a different style in the two of them. One example would be this CSSZengarden submission: (http://www.csszengarden.com/?cssfile=http://icant.co.uk/zen/sample.css).

The reason for these websites is to show how much more a browser that properly supports CSS2 can offer. This technique is called progressive enhancement (http://css-discuss.incutio.com/?page=ProgressiveEnhancement), or graceful degredation (http://www.anybrowser.org/campaign/
abdesign.html#degradability) - depending on which way you look at it – from newer to older or older to newer browser.

It is nothing new - clever Web developers have done to same to send a basic style sheet to older browsers like Netscape 4, and a different one to more advanced browsers:

<link rel="StyleSheet" href="basic.css" type="text/css">

<style type=”text/css”>@import “advanced.css”;</style>

Netscape 4 does not grasp the @import directive and applies basic.css exclusively. More modern browsers also read advanced.css and overwrite or re-use what has been defined in basic.css. The same can be done today for yet a newer breed of browser. This can be achieved in several ways.