  X-ray propagation-based imaging techniques are well-established at
synchrotron radiation and laboratory sources. However, most reconstruction
algorithms for such image modalities, also known as phase retrieval algorithms,
have been developed specifically for one instrument by and for experts, making
the development and spreading of the use of such techniques difficult. Here, we
present PyPhase, a free and open-source package for propagation-based
near-field phase reconstructions, which is distributed under the CeCILL
license. PyPhase implements some of the most popular phase-retrieval algorithms
in a highly-modular framework supporting the deployment on large-scale
computing facilities. This makes the integration, the development of new
phase-retrieval algorithms, and the deployment on different computing
infrastructures straight-forward. To demonstrate its capabilities and
simplicity, we present its application to data acquired at synchrotron MAX~IV
(Lund, Sweden).
