XSL

Extensible Style sheet Language (XSL) is a language for expressing style sheets. Given a class of arbitrarily structured XML documents or data files, designers use an XSL style sheet to express their intentions about how that structured content should be presented; that is, how the source content should be styled, laid out, and paginated onto some presentation medium, such as a window in a Web browser or a hand-held device, or a set of physical pages in a catalog, report, pamphlet, or book.

It consists of two parts:

• a language for transforming XML documents known as XSL Transformations (XSLT), and
• an XML vocabulary for specifying formatting semantics.

Formatting is enabled by including formatting semantics in the result tree. Formatting semantics are expressed in terms of a catalog of classes of  formatting objects. The nodes of the result tree are formatting objects. The classes of formatting objects denote typographic abstractions such as page, paragraph, table, and so forth. Finer control over the presentation of these abstractions is provided by a set of formatting properties, such as those controlling indents, word- and letter-spacing, and widow, orphan, and hyphenation control. In XSL, the classes of  formatting objects and  formatting properties provide the vocabulary for expressing presentation intent.

On August 28, 2001, XSL became a W3C Proposed Recommendation.