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.

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 if the web is at the highest of prosperity. For example, in case we create technical documents, contracts or reports for customers in XML, the technology to print these to paper is required. At the same time XML is expanding, the need of XSL will be highly required which is the technology of printing paper beautifully depending on the specification of special printing layouts.

Printing forms

Another field where XSL is expected to be important is print XML data with layout and output it to PDF.

For example, when we convert form data into XML, it is natural to input data on browser form and specify the data format is XML, output to paper by specifying XML format. Therefore, XML is a tag mapped form, it is necessary for men to understand the contents and confirm XML to print by giving format type, or to output digitalized paper such as PDF.

In this industry, special form printing tool has been popular currently in use. Special form printing system specifies the special format in the traditional way. While, XSL can specify layouts flexibly by creating world standard stylesheet. As the result, we can 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 instead of special form printing tool.


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

According to the spread of XML as a data format exchanging among computers, it is inevitable that the contents will increase which human, not computer, must confirm and the contents which must be changed into visual format.

XSL is a specification to give a format to XML.XSL is separated from XML, it is also possible to apply multiple XSL specification 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 besides.

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, output to paper, output to specified media such as XSL-FO to PDF.

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

By changing XSL, we can change layouts flexibly. For example, formatting server converts documents to PDF currently, then a little after, it converts business forms to PDF. Such flexibility is derived from separating contents in XML, formats in XSL. It is not available by the special system in a traditional way.

For the reason stated above, we can easily expect that XSL will become much important for highly utilizing the web in the future. XSL is not a focus of public attention yet, but it is quite sure that XSL is the most ikely chosen, and has a bright future. We highly recommend to take this high technology immediately into your business and make use of it for the web.