XProc is an XML transformation language for processing documents in pipelines: chaining conversions and other steps together to achieve the desired results. It can handle documents in XML, HTML, JSON, text and binary. The current (stable) version is 3.0. While XProc 1.0 is a W3C Recommendation, XProc 3.0 is a standard developed by the W3C XProc Next Community Group. Its main characteristics are:

Example

The following is a (very) simple XProc pipeline: So if you supply the following XML document to this pipeline: It comes out as: The exact date and time recorded in the attribute is of course dependent on the date and time the pipeline is executed.

Understanding and learning XProc

The learning page of the XProc website contains links to all the learning and reference materials the XProc community group is aware of. There is a special 101 section with introductory learning materials.

History

Ideas for something, some programming language, for processing were there right from the beginnings of XML, at the end of the twentieth century. But it was not until the end of 2005 that the W3C started a working group called the XML Processing Model Working Group. this resulted in the recommendation for XProc 1.0 dated May 11, 2010. There were various attempts to create working XProc 1.0 processors. The only two currently available as open source products that implement the full 1.0 standard are XML Calabash and MorganaXProc. After the release of version 1.0, the XProc working group continued debating a next version. Ideas were raised for version 2.0. This was based on a non-XML syntax which didn’t raise a lot of support from the community. Engagement in the working grouped waned and in 2016 it ceased to exist. In June 2017 the XProc Next Community Group was founded and started working on a new version, now completely XML based. Because this was a completely different approach than the 2.0 initiative, the version number was increased to 3.0. A stable version was released on 12 September 2022. In 2024 the working group started work on a minor update to 3.1.

Implementations

The following processors support the XProc 3.0 standard:

Older versions

The following processors support the XProc 1.0 standard. There were several other XProc 1.0 implementations, but these were either incomplete or are not maintained.

Logo

This is the logo of XProc. It was created by Bethan Tovey-Walsh. The fish is called Kanava, which is Finnish for pipeline.