Proprietary software
computer software released under a license restricting use, study or redistribution
Proprietary software is software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA-bound software—from making use of the software on their own, thereby restricting their freedoms.
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.
Some open-source software can be described as proprietary, as copyright is retained by its authors and may be concentrated through Contributor License Agreement, enabling relicensing under more restrictive terms.
Origin
Until the late 1960s, computers—especially large and expensive mainframe computers, machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold. Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors usually provided the source code for installed software to customers. Customers who developed software often made it available to the public without charge. Closed source means computer programs whose source code is not published except to licensees. It is available to be modified only by the organization that developed it and those licensed to use the software.
This brief starts where responsible research should: with the source description of “Proprietary software” as computer software released under a license restricting use, study or redistribution. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the science & nature register because the source frames it as computer software released under a license restricting use, study or redistribution. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Sep 8, 2026. The linked authority identifier is Q218616. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1969.
A general summary may omit uncertainty, sample limits or methodological disagreement that is explicit in the technical record. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Proprietary software”, its source revision and the description used here.
- Expand the search: follow Proprietary software primary sources, Proprietary software archive and Proprietary research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Proprietary software”?
- Which observation, specimen, dataset or publication supports the account?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Proprietary software” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.