Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering. Complementary terms include free software, licensed by the owner under more permissive terms, and public domain software, which is not subject to copyright and can be used for any purpose. Proponents of free and open source software use proprietary or non-free to describe software that is not free or open source. In the software industry, commercial software refers to software produced for sale, which is a related but distinct categorization. According to Eric S. Raymond, in the Jargon File, "In the language of hackers and users" it is used pejoratively, with the meaning of "inferior" and "a product not conforming to open-systems standards".
Contributions by Gronky, Jimmi Hugh, and RossPatterson.