Gammapy is an open-source Python package for gamma-ray astronomy built on Numpy, Scipy and Astropy.
It is used as core library for the Science Analysis tools of the Cherenkov Telescope Array (CTA), recommended by the H.E.S.S. collaboration to be used for Science publications, and is already widely used in the analysis of existing gamma-ray instruments, such as MAGIC, VERITAS and HAWC.

Please remember to acknowledge and cite the use of gammapy!