In short, an open system standard is an interface specification - a specification that describes services provided by a software product - to which any vendor can build products. There are two important points. First, the specification is available to any vendor and evolves through a consensus process that is open to the entire industry. Second, the specification defines only an interface, so different vendors can provide the standard interface on their proprietary operating systems (see fig. 2.1).
Open system standards will make it possible to develop standard software components that can be implemented on a wide variety of hardware, making a software components industry economically practical. But, open system standards do not solve all problems associated with building interchangable software components. Software designers need to understand the capabilities and limitations of software standards, and how to deal with these limitations. This article describes important open system standards and explains how they can be used to build portable, interoperable application software components.
Figure 2.1: Open System Approach.