Open system (computing)
From Free net encyclopedia
Open systems are computer systems that provide either interoperability, portability, or freedom from proprietary standards, depending on user's perspective.
For years the term was applied loosely to the many flavors of Unix. Since the emergence of The Open Group's Single UNIX Specification, any operating system that supports the Unix APIs (z/OS, for example) can reasonably be classed as an open system.
Unix vendors for years used the term as a marketing advantage — who, after all, doesn't want an "open system"? The term gained particular traction in opposition to 1970s and 1980s vintage IBM mainframes. However, in a remarkable turnabout, Linux-oriented vendors are now claiming the term as their own. Consequently the IBM mainframe with its open source Linux on zSeries is now widely regarded as a truly open system — it runs more Linux instances than any server, after all — while servers running proprietary, closed source UNIX and Microsoft Windows are not. In fact, this new market pressure has encouraged Sun Microsystems to start opening up the source code to its Solaris UNIX operating system.