Degrees of Openness
The open source software movement has received a lot of press coverage in recent years. A result of this is many people associating the term "open" with open source software. This popular definition of "openness" is incomplete. Openness affects many aspects of computing besides freedom to view and modify source code. Shrewd proprietary computer companies have been able to take advantage of popular misconceptions about openness, masking their products in partial degrees of openness, then applying the "open" label. We should understand the different forms of openness and how they apply to the many facets of computers, software, systems, and even warranties and service agreements.
An important concept to keep in mind when thinking about openness is that open doesn't always mean transparent (as in having access to source code, hardware specs or other internal information). Prime examples of this are APIs, which provide standard (that is, open) programmatic interfaces to software libraries or applications.
An open component, whether software or hardware, can be proprietary due to licensing.