Open architecture

An architecture whose specifications are public. This includes officially approved standards as well as privately designed architectures whose specifications are made public by the designers. The opposite of open is closed or proprietary.The great advantage of open architectures is that anyone can design add-on products for it. By making an architecture public, however, a manufacturer allows others to duplicate its product. The IBM PC, for example, was based on open architectures, and has spawned an entire industry of IBM clones. In contrast, the Macintosh architecture and operating system has been predominantly closed.