http://lm.i2p/nojs/knowledge/why-monero-is-open-source-and-decentralized
Open source software A free, open source software (FOSS) project is one in which the code is licensed in such a way that it is available for viewing, changing, auditing, and copying by anyone and everyone. In contrast, the code of proprietary software is hidden, and kept as a business secret that is not shared for fear of competition copying the hard work that the creator paid for or made.