What is XSL Specification?

Extensible Stylesheet Language XSL is a specification developed by W3C (World Wide Web Consortium) for XML documents to be layout and printed beautifully. W3C has contributed to the development of the Web, standardization of the Web.

German Reference Guides for XSL-FO

  • XSL-FO Die Referenz by Manuel Montero-Pineda & Steffen Herkert – A comprehensive German reference guide to XSL-FO for all levels from beginners to experts.
  • XSL-FO Vollständige Referenz by Manfred Krüger – The complete German reference guide to XSL-FO with the latest Antenna House XSL Formatter V6.5 extensions.

XSL Specification has just become a W3C Recommendation and is not a focus of public attention. But it is expected to play an important role because it is used with XSLT for the Web. We will explain what we can do with XSL and why it is important.


XSL Specification defines objects that specify the page format, various types of objects such as paragraph, table, list. They are called Formatting Objects (FO). And it defines the page size, the font size, others as FO properties.

Print documents with an XSL-FO Engine

By using XSL Specification, we can describe how the XML data and documents are formatted professionally. In other words, the layout that depends on the special printing technology is available as follows.

  • Changing various page formats
  • Footnote
  • Header, Footer
  • Sidebar
  • Column
  • Changing progression direction of lines or characters
  • Generating table of contents, leader, page number, automatically
  • Mutual reference
  • Index

It will be necessary to print XML documents to paper even when other formats increase in popularity. For example, in case we create technical documents, contracts or reports for customers in XML, the technology to print these to paper is required. As XML is expanding in use, the need for XSL; the technology of printing beautiful layouts, will increase .

Printing forms

Another field where XSL is expected to be important is printing forms.

In this industry, special form printing tools have been popular in use. Traditionally, special form printing systems specifies the special format. While, XSL can specify layouts flexibly by creating standard stylesheets. As a result, we can an develop open system in a short period and at low cost using XSL.

In the future we expect that XSL will expand as an open solution over special form printing tools.


Cases where we exchange data between companies (B2B), between company and individual (B2C), or inside company, among branch office, sales office, local office, and head office, using XML as an exchanging format is expected to increase more and more and so will the need for a compliant XSL-FO processor.

Based on the percentage of XML used as a data format exchanging among computers, it is inevitable that the amount of contents will increase, which a human, not computer, must confirm and therefor the content must be changed into visual format.

XSL is a specification to give a format to XML.XSL is separate from XML. It is possible to apply multiple XSL specifications to one XML and output various layouts. That is, by using XSL technology we can generate various presentations from one data source and can do it very easily.

XSL Formatter is a formatting engine that formats XML according to the instruction described in XSL and prints them to paper.In other words, XSL Formatter takes XML documents or form data and layout format information described in XSL, then formats them, and outputs to specified media such as PDF.

We can also send XML and XSL to XSL Formatter on a server remotely from the browser. We can also format on standalone PC and output to a connected printer.

XSL allows flexibility with layouts and formats. For example, you could have a formatting server which converts documents to PDF currently, then a little after, it converts business forms to PDF. Such flexibility is derived from separating content and form. The traditional methods of publishing do not offer this flexibility.

For the reason stated above, we can easily expect that XSL will become much important for the web in the future. XSL is not a focus of public attention yet, but it is quite certain that XSL will have a bright future. We highly recommend implementing this technology immediately into your business and make use of it for the web.