Topic summary
Closed-source software
Extracted from the Wikipedia article Proprietary software.
Proprietary software, sometimes also referred to as Proprietary and Internal Source Software (PISS, an informal and derogatory antiversion of the FOSS acronym for Free and Open Source Software), is a subset of non-free software, a term defined in contrast to free and open-source software; non-commercial licenses such as CC BY-NC are not deemed proprietary, but are non-free. Proprietary software may either be closed-source software or source-available software.