proprietary
     adj : protected by trademark or patent or copyright; made or
           produced or distributed by one having exclusive rights;
           "`Tylenol' is a proprietary drug of which
           `acetaminophen' is the generic form" [ant: {nonproprietary}]
     n : an unincorporated business owned by a single person who is
         responsible for its liabilities and entitled to its
         profits [syn: {proprietorship}]
Source: WordNet® 2.0

proprietary adj. 1. In {marketroid}-speak, superior; implies a product
   imbued with exclusive magic by the unmatched brilliance of the company's
   own hardware or software designers. 2. In the language of hackers and
   users, inferior; implies a product not conforming to open-systems
   standards, and thus one that puts the customer at the mercy of a vendor
   able to gouge freely on service and upgrade charges after the initial
   sale has locked the customer in. Often used in the phrase "proprietary
   crap". 3. Synonym for closed-source, e.g. software issued in binary
   without source and under a restrictive license.

   Since the coining of the term {open source}, many hackers have made a
   conscious effort to distinguish between `proprietary' and `commercial'
   software. It is possible for software to be commercial (that is,
   intended to make a profit for the producers) without being proprietary.
   The reverse is also possible, for example in binary-only freeware.


Source: The Jargon File