One of the reasons for the creation of the Open Source "brand" is that the term "Free Software" is easy to misunderstand in English. Unlike some other languages, the word free in English represents two distinct concepts:
- Available at no cost
- Possessing freedom
The second definition is the relevant one in terms of Free Software, but when talking about software it’s easy to expect the first. The term "freeware" is typically used to describe software distributed using the first definition. Much Free Software is also freeware; that is, you can download it and run it without paying anyone. A lot of Free Software isn’t free, however. If you buy some custom software and receive all the rights to it, then it was distributed to you as Free Software, but not freeware.
To attempt to alleviate this confusion, the word open was used instead. Unfortunately, "open" has a lot of meanings in the software world. OpenVMS is one of the oldest examples; it gained the Open designation because it conformed to POSIX, an open standard.
The other part of the name is "source," and this also causes some confusion. By focusing on the availability of the source, rather than the availability of the freedom, programs like Microsoft’s Shared Source Initiative are able to piggyback on the term. To someone unfamiliar with Free Software and Open Source software, it may sound as if Shared Source is Open Source, because you can download and read the source. This isn’t the case, however, since often you’re not allowed to distribute the software or any derived works.
Recently, the term Software Libre has become popular. This Spanish translation of "Free Software" is not as ambiguous, since Spanish distinguishes between "free as in freedom" (libre) and "free as in price" (gratis). Of course, the downside of this term is that it requires a basic knowledge of Spanish for people to understand it.