The r.mblend experience In 2017, I had the opportunity to implement a DEM blending algorithm that had been theorised earlier by my colleague João Leitão. It was somewhat natural to develop it as a GRASS add-on, since I have long relied on it for map algebra and other geo-spatial computations. That is how the r.mblend add-on was born. Five years passed without me committing again to r.mblend. In the meantime many important things changed, GRASS version 8 was released and code management moved from SVN to git/GitHub.