For almost 20 years, we have been working at IRAP (Toulouse, France) on the development of the CASSIS (Centre d’Analyse Scientifique de Spectres Instrumentaux et Synthétiques) line analysis and modelling software, which is freely available to the community. CASSIS ( https://cassis.irap.omp.eu) is being developed at IRAP as part of the French ‘Observation Services’, designed to develop and supply free analysis tools and databases (based on observations and/or theories) to the worldwide astrophysics community. In this talk, I will describe the capabilities of CASSIS in its current distributed version (v6.4, in Java) - initially designed to analyse single spectra observations - and work in progress to extend these capabilities to the analysis and modelling of datacubes, enabling maps of a source's physical parameters to be produced. This new version is developed in Python 3, and we plan to distribute it via Astropy. We are currently debugging the software, implementing and testing new use cases developed with beta testers (some of whom are here at IRyA). Finally, I will present some results obtained on different types of astronomical sources, low- and high-mass star-forming regions, PDRs, Xgal sources…, from observations made with different types of single-dish telescopes (using the OTF mapping mode) and with interferometers.