Cascading style sheets (CSS) are a powerful mechanism to customize
HTML rendering inside a Web browser. The CSS2
specification comes from the W3C, and has now reached the status of
a W3C recommendation. See http://www.w3.org/TR/REC-CSS2/.
The CSS syntax is a great improvement over the .Xdefault resource mechanism of the X
Window System. The basic idea remains the same: matching a pattern
and setting resource values. CSS is devoted to HTML rendering,
matching HTML tags and setting style values. XML is another CSS
target, especially as used within the SVG (Scalable Vector
Graphics) recommendation from the W3C.