Main Page | See live article | Alphabetical index An open system is a term: In science, where an open system (system theory) means a system in which matter or energy can flow into and/or out of the system, in contrast to a closed system in which no energy or matter may enter or leave the system. In computing, where an Open Systems is a computer operating system that provides interoperability, portability or both, particularly Unix systems. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.