Software can be used in commercial contexts to make Business. Therefore the term "commercial software" is a misnomer. The opposite of Open Source and Free Software is "proprietary software".
Free and Open Source Software
Free Software and Open Source describe a licensing model that promotes the commercial use of the software by preventing individuals to restrict distribution to their own terms. "Their own terms" refers to the notion of property, hence the terminology "proprietary" - to be in someone's property.
Proprietary Licensed Software
Proprietary licenses (also called Restricting licenses) can make it a lot more difficult to use the corresponding software commercially due to complicated and complex usage restrictions. In many cases license definitions have to be modified to be applicable to national law. Proprietary licenses tend to be modified more frequently due to changes in the market, competitor's strategies, the law, and so on. This potential for change makes it much more difficult for a professional and commercial users to calculate TCO, protect their investment and implement scalability.
For all of the above reasons it does not make much sense to use the term "commercial software" as opposed to Open Source or Free Software. If the two opposing license models are to be differentiated, then the correct term is "proprietary software".
Unfortunately the term "proprietary" is also used in the context of interoperability and describes software that does not follow open standards. From this perspective the term "proprietary" can sometimes be applied to Free and Open Source Software interfaces. Any software that does not follow standard interfaces or file formats has "their own" (proprietary) interface definitions. In this case the "owner" is the "software" and the object of ownership is the interface or data format. Do not confuse this with licenses where the "owner" is an individual or an organization and the object of ownership is the software.
The "owner" of a "software" automatically "inherits" what is "owned" by the software. Thus the proprietary restrictions on the software also apply to the interfaces. One good example where this problem has been recognized and is now being changed is the Google-owned format KML. Google has transferred the ownership (copyright) of KML to the OGC so that the interface can become an open standard.
If you have a more adept, clean, expert, skilled and smart way of expressing these issues without using so many "quotes" please feel free to help User:Seven clean this terminological mess up.
More Links and Definitions
- There was some discussion on the Wikipedia page on Commercial Software which eventually ended up as a redirect to "Business Software" (linked by --Seven 11:18, 29 July 2007 (CEST)).
- Don't oppose Free Software and Commercial Software by Jan Wagner (2004)
- Feel free to add more links that make sense in this context