The CPL comprises a set of ISO-C libraries that provide a comprehensive, efficient and robust software toolkit to develop astronomical data-reduction tasks (known as recipes). These data-reduction tasks can then be executed manually by a user, or can be triggered in an automated data-reduction framework (known as pipelines) which are used at ESO to monitor the health status of VLT instruments, for quick-look data processing at the observatory, and the creation of data products available from the ESO archive facility.