History of CSS

Style sheets have existed in one form or another since the beginnings of Standard Generalized Markup Language (SGML) in the 1980s. Cascading Style Sheets were developed as a means for creating a consistent approach to providing style information for web documents. As HTML grew, it came to encompass a wider variety of stylistic capabilities to meet the demands of web developers. This evolution gave the designer more control over site appearance, at the cost of more complex HTML. Variations in web browser implementations, such as ViolaWWW and WorldWideWeb, made consistent site appearance difficult, and users had less control over how web content was displayed. Robert Cailliau wanted to separate the structure from the presentation. The ideal way would be to give the user different options and transferring three different kinds of style sheets: one for printing, one for the presentation on the screen and one for the editor feature.

Difficulty with Adoption

The CSS 1 specification was completed in 1996. Microsoft's Internet Explorer 3 was released in that year, featuring some limited support for CSS. But it was more than three years before any web browser achieved near-full implementation of the specification. Internet Explorer 5.0 for the Macintosh, shipped in March 2000, was the first browser to have full (better than 99 percent) CSS 1 support, surpassing Opera, which had been the leader since its introduction of CSS support 15 months earlier. Other browsers followed soon afterwards, and many of them additionally implemented parts of CSS 2. As of August 2010, no (finished) browser had fully implemented CSS 2, with implementation levels varying (see Comparison of layout engines (CSS)). Even though early browsers such as Internet Explorer 3 and 4, and Netscape 4.x had support for CSS, it was typically incomplete and had many bugs that prevented their implementations from being usefully adopted. When later 'version 5' browsers began to offer a fairly full implementation of CSS, they were still incorrect in certain areas and were fraught with inconsistencies, bugs and other quirks. The proliferation of such CSS-related inconsistencies and even the variation in feature support has made it difficult for designers to achieve a consistent appearance across browsers and platforms. Some authors resorted to workarounds such as CSS hacks and CSS filters. Problems with browsers' patchy adoption of CSS, along with errata in the original specification, led the W3C to revise the CSS 2 standard into CSS 2.1, which moved nearer to a working snapshot of current CSS support in HTML browsers. Some CSS 2 properties that no browser successfully implemented were dropped, and in a few cases, defined behaviors were changed to bring the standard into line with the predominant existing implementations. CSS 2.1 became a Candidate Recommendation on February 25, 2004, but CSS 2.1 was pulled back to Working Draft status on June 13, 2005, and only returned to Candidate Recommendation status on July 19, 2007. In the past, some web servers were configured to serve all documents with the filename extension .css as mime type application/x-pointplus rather than text/css. At the time, there was a software product on the market to convert PowerPoint files into Compact Slide Show files using the .css extension.

Source: Wikipedia | 3-17-2024