Proprietär

Proprietär (or proprietär) is a German adjective meaning owned by a private person or company and used to describe property and rights that are controlled by a private owner. In practice it signals that access, use, modification and distribution are governed by specific terms set by the owner, typically through licenses or contractual restrictions. In German usage it contrasts with terms like open or public when referring to standards, formats, or software.

Proprietäre Software refers to software whose source code is not publicly available, distributed under restrictive licenses, often using vendor-specific file formats, and where the vendor retains control over distribution, updates and compatibility. Such software may require paid licenses and can create vendor lock-in. It is commonly contrasted with open-source software or free software, where the code is accessible and licenses permit broader reuse and modification.

Proprietär can also apply to other areas of geistiges Eigentum, such as patents, trademarks, copyrights or trade secrets. In these contexts the owner holds exclusive rights, and unauthorized use may be restricted or made illegal. Licensing, nondisclosure agreements or contracts define what third parties may do with the proprietary material.

Etymology: The term derives from the French propriété meaning owner, via German usage dating from the 19th or 20th century. In German, proprietär is often used with nouns such as Software (proprietäre Software) or Standards (proprietäre Standards). The concept is central to debates about interoperability, competition and user rights, balancing proprietary control against openness and standardization.