"Proprietary software" is a term used to describe software in which the user does not control what it does or cannot study or edit the code, in contrast to free software.

The FSF applies the designation to any software that is non-free or partially free. The modification, use and redistribution is prohibited, or requires express permission from the originator. "Non-free" is a customary designation for software that fails the Debian Free Software Guidelines, which follow the same basic idea of software freedom and on which the Open Source Initiative definition of open source is based. Proprietary means that some individual or company holds the exclusive copyrights on a piece of software, at the same time denying other people the access to the software's source code and the right to copy, modify and study the software.

The term proprietary means "privately owned and controlled". Hence software can remain proprietary even when source code is made publicly available, if control over use, distribution, or modification is retained (e.g., the commercial version of SSH and the Microsoft Shared source licence programme.) On the other hand, software is considered non-proprietary once it is released with a license that would permit others to "fork" the software and release their own modified versions without onerous restrictions, even though the copyright may remain in the hands of a single individual. At least in theory, control has been conceded.

Many types of software that are offered free of charge are proprietary, such as freeware, shareware and abandonware. This is because the source code in those distribution schemes is closed, or modification is prohibited, or redistribution requires express permission of an individual, organisation or company.

See also

• closed source
• intellectual property
• non-proprietary software
• open source
• open standard
• Richard Stallman
• vendor lock-in

External links

• FSF software categories
• By Reading This Article, You Agree To Subscribe To This Magazine for 25 Years ...: Shrinkwrap Licenses: Threat or Menace? (Leo L. Schwab, Microtimes, November 1996)