It is therefore crucial to provide a license, and vital to choose a relevant one. As the gold standard for proteomics software development, we recommend using a standard OSS license like Apache 2.0, MIT, BSD, LGPL, and GPL; the full list of applicable licenses can be found at ( ). These licenses are all well known, are in use across many fields, and are well understood by the community. Additionally, they are compatible with the FAIR principles and the OSI guidelines . These established licenses moreover all have a clear definition of what is allowed and what is not, and how the software can be distributed, reused, and cited.