The first implementation of CSS was initially drawn up in 1996 and then released in 1999. By 2001 all new browser releases supported it, but even so the standard was once again revised in 2008. At the same time (beginning in 1998) CSS 2 was already being drawn up, and the standard was eventually completed in 2007 - but revised again in 2009. Then there's CSS 3, which commenced development in 2001, and of which some features were proposed only as recently as 2012. Therefore the development process will likely continue for some time before a final recommendation for CSS 3 is agreed. And even though CSS 3 isn't yet complete, people are already beginning to put forward suggestions for CSS 4 (and even ideas for HTML6 too).