Formatting Objects Processor

Apache FOP
Original author(s)	James Tauber
Developer(s)	Apache Software Foundation
Stable release	2.10 / 1 October 2024; 7 months ago
Repository	github.com/apache/xmlgraphics-fop ;
Written in	Java
Operating system	Cross-platform
Type	XSL-FO
License	Apache License 2.0
Website	xmlgraphics.apache.org/fop

Formatting Objects Processor (FOP, also known as Apache FOP) is a Java application that converts XSL Formatting Objects (XSL-FO) files to PDF or other printable formats. FOP was originally developed by James Tauber who donated it to the Apache Software Foundation in 1999. It is part of the Apache XML Graphics project.

FOP is open source software, and is distributed under the Apache License 2.0.

Current status

The latest version of Apache FOP is 2.10.^[2] This is the seventeenth stable release.^[3]

Major limitations

Most important elements added in XSL-FO 1.1 (flow maps, table markers, indexes. etc.) are not available ^[4]

In addition, older XSL-FO 1.0 features are still not fully supported including automatic table layout, floats and more.

Input support

Apache FOP supports embedding a number of image formats in the XSL-FO (through the <fo:external-graphic> element). These include:

SVG
PNG
Bitmap BMP
PostScript (as EPS)
JPEG
Some TIFF formats.

Apache FOP implements the <fo:float> element with some limitations.^[5] In versions prior to 2.0, external graphics objects were limited to being drawn inline or in a block with no wrapped text.