Mass spectrometry is an analytical technique that measures the mass and abundance of small molecules with very high precision. However, the data coming from mass spectrometry instruments is complex and multi-dimensional. MZmine is a very successful open-source graphical software for mass-spectrometry data processing implemented in Java. It contains a library of algorithms and powerful visualization modules. The publication about MZmine 2 (Pluskal et al., BMC Bioinformatics 2010) has been cited over 1400 times. A new version, MZmine 3, which is currently under development, is based on JavaFX for its user interface. Our main goal is to provide a user-friendly, flexible and easily extendable software with a complete set of modules covering the entire mass-spectrometry data analysis workflow. MZmine participated in GSoC in 2017, 2018, and 2019 as part of the OpenChemistry umbrella organization. Due to great interest from both students and mentors, we decided to participate as an independent organization in 2020!