The Common Pipeline Library

Latest News

CPL version 6.2 has been released - (23-Nov-2012)

CPL Title Graphic

Quick Links

  • News. The most recent announcements along with the current project status.
  • Introduction. Find out all about the CPL project and its history
  • Download. A repository with all the publicly available CPL files.
  • Documentation. Collection of all the relevant information about using the CPL.
  • Useful links to instruments using CPL, software development tools and more.
  • Contact the CPL team to report bugs or make suggestions/comments


The Common Pipeline Library (CPL) comprises a set of ISO-C libraries that provide a comprehensive, efficient and robust software toolkit. It forms a basis for the creation of automated astronomical data-reduction tasks (known as "pipelines").

The CPL was developed to standardise the way VLT instrument pipelines are built, to shorten their development cycle and to ease their maintenance. However, it may be more generally applied to any similar application, and the details of the CPL code have been engineered in a way to make the library portable and flexible, as well as minimising external dependencies.

The CPL provides a host of functionality, presented in a clear, generic and uniform manner. Among its many features, the CPL offers:

  • many useful low-level data types (images, tables, matrices, strings, property lists, ...),
  • many fundamental statistic, arithmetic and conversion operations for these data types.
  • medium-level data access methods (e.g. a data abstraction layer for FITS files),
  • data table organisation and manipulation,
  • keyword/value handling and management,
  • a standardised application interface for pipeline recipes, and,
  • support for dynamic loading of recipe modules.

Despite the current bias towards instrument pipeline development, the library also provides a variety of general-purpose image- and signal-processing functions, making it an excellent framework for the creation of more generic data-handling packages.

For more information about the CPL project, please see the web pages whose links appear at the top of this page.