Open architecture

Open architecture is a type of computer architecture or software architecture that allows adding, upgrading and swapping components. For example, the IBM PC and Apple IIe have an open architecture, whereas the Apple IIc and Amiga 500 computers have a closed architecture. In a closed architecture, the hardware manufacturer chooses the components, and they are not generally upgradable by the end user.

Open architecture allows potential users to see inside all or parts of the architecture without any proprietary constraints. Typically, an open architecture publishes all or parts of its architecture that the developer or integrator wants to share. The open business processes involved with an open architecture may require some license agreements between entities sharing the architecture information.