XSL-FO

Extensible Stylesheet Language Formatting Objects

Part of the XSL (Extensible Stylesheet Language) specifications is a family of languages for transforming and rendering XML documents. XSL-FO is used to format XML data and is most often utilized for generating PDFs or other printable formats from XML data.

The primary use case for XSL-FO is to describe the visual formatting of an XML document for presentation to users on paper, on screen, or in other media. An XSL-FO document is typically an XML document that uses specific tags defined by the XSL-FO standard to dictate how the content of the XML data should appear in its final output form.

XSL-FO is a powerful but complex technology that provides detailed control over page layout, including support for headers, footers, page numbers, tables, and other features you would expect in a typesetting and page layout language. It’s designed to be used with XSLT, which transforms XML data into an XSL-FO document. An FO processor can then process this XSL-FO document to create the final formatted output, such as a PDF. The advantage of using XSL-FO is that it is a standards-based document format, ensuring consistency across different systems and devices.