XSL-FO (Extensible Style Sheet Language-Formatting Objects) is a markup language which generates PDFs from XML files (along with other types of files). Users take an original XML document, run it through an XSLT transform which then creates an XSL-FO document, and finally send it to an FO processor which converts the document into one of the output formats. Whereas HTML is an unpaged language, XSL-FO is built around the concept of pages, and as such it provides a great deal of control over textual layout.

XSL-FO and INDI

XSL-FO is used in INDI to generate PDFs of reports, which can then be printed and filed in physical case files.