HARP originally stands for the Hirlam-Aladin R Package for verification (although R package is extensively used in the HARP, the tool package is not limited to the R language and utilities).
The main goal of the HARP development is to provide the HIRLAM-ALADIN community with suitable tools for probabilistic and mesoscale forecast verification, the latter with focus on spatial aspects. The plan for developing this joint package dates back to the ALADIN Workshop & HIRLAM All Staff Meeting in Marrakech in 2012.
Two Working Weeks were dedicated to verification in 2012 & 2013 and verification was also part of the 2014 forecasters meeting.
At the release of V1, application of HARP for probabilistic forecast is in good shape while the functionality of HARP for spatial verification remain to be worked on.
See more information about HARP on the HIRLAM system wiki : https://hirlam.org/trac/wiki/HARP .