Proprietary software
From Free net encyclopedia
Proprietary software is software that has restrictions on using and copying it, usually enforced by a proprietor. The prevention of use, copying, or modification can be achieved by legal or technical means. Technical means include releasing machine-readable binaries only, and withholding the human-readable source code. Legal means can involve software licensing, copyright and patent law. Proprietary software can be sold for money as commercial software or available at zero-price as freeware.
The term is used by the Free Software Foundation to describe software that is not free software or semi-free software. Technically, the term means software that has an owner who exercises control over the software. Thus, it can be used for all software that is not in the public domain. However, the FSF uses the term to highlight that the owner is of prime importance, in contrast to "free software", where the freedom of computer users is of prime importance. The adjective "proprietary" also avoids confusion with the phrase "commercial software", since free software can also be sold and used for commercial purposes.
The term "non-free software" (or "nonfree") is used interchangeably and about as often. Richard Stallman sometimes uses the term "user subjugating software", while Eben Moglen sometimes talks of "unfree software". The term "non-free" is generally used by Debian developers, but they too sometimes talk of "proprietary software". Open Source Initiative prefers the term "closed source software".
Some free software packages are available under proprietary terms. Examples include MySQL, Sendmail and SSH. The original copyright holders for a work of free software, even copyleft free software, can use dual-licensing to allow themselves or others to redistribute proprietary versions. Non-copyleft free software, or free software "with a permissive license", allows anyone to make proprietary redistributions.
Some proprietary software comes with source code or provides offers to the source code. Users are free to use and even study and modify the software in these cases, but are restricted by either licenses or non-disclosure agreements to redisribute modifications or simply share the software. Examples include proprietary versions of SSH, Pine or the Microsoft Shared source license program.
Like Freeware, Shareware is proprietary software available at zero price for a trial period. Proprietary software that has a copyright that isn't enforced but is used illegally by users is called "abandonware" and may include source code. Some abandonware has its source code placed in the public domain either by its author or copyright holder and is therefore free software, not proprietary software.
Well known examples of proprietary software include Microsoft Windows, RealPlayer, Adobe Photoshop, Mac OS, WinZip and UNIX.
See also
ca:Programari privatiu de:Proprietäre Software es:Software no libre fr:Logiciel propriétaire it:Software proprietario nl:Propriëtaire software no:Proprietær programvare ru:Собственническое ПО sk:Proprietárny softvér th:Proprietary software