Cargos y funciones

A CSS file can be created and edited “by hand,” i.e., with a text editor, but you can also write a program in ECMAscript, Java or some other language, that manipulates a style sheet. This is in fact so common, that there are software libraries of useful functions available. To help in porting such program & libraries to different computer platforms, W3C has developed a specification called CSS-DOM, that defines a set of functions that all such libraries must provide.

The CSS Document Object Model is an API (Abstract Programming Interface) for manipulating CSS (and to a certain extent also other style languages) from within a program. An API is the specification of a software library. You can see it as a manual: it describes the functions and their parameters, but doesn't contain the actual code.

There are several CSS-DOM libraries available, for different platforms. Many of them are free. Many browsers have a CSS-DOM library built-in, for use by ECMAScript programs.

SAC (Simple API for CSS) is a complement to the CSS-DOM. The CSS-DOM contains functions to manipulate a style sheet after it has been loaded into memory; the functions defined by SAC help in parsing a style sheet, i.e., in transferring a style sheet from a file into memory.