This specification describes the syntax and semantics of XProc 3.1: An XML Pipeline Language, a language for describing operations to be performed on documents.

An XML Pipeline specifies a sequence of operations to be performed on documents. Pipelines generally accept documents as input and produce documents as output. Pipelines are made up of simple steps which perform atomic operations on documents and constructs such as conditionals, iterations, and exception handlers which control which steps are executed.

Supersedes: XProc 3.0: An XML Pipeline Language