A book authored by Yves AUDA has been published, handling the analysis of the critical zone with open-source softwares GRASS and QGIS: field sampling, hydrological models, landscape analysis, remote sensing mapping, digital elevation models, etc. Theory and exercises are based on data from the M-TROPICS/MSEC CZO in Northern Laos, gathered within the TecItEasy ANR project. More details at editor’s web page.