What (who) is Common Applications Environment - definition

In computer software, an operating environment or integrated applications environment is the environment in which users run application software. The environment consists of a user interface provided by an applications manager and usually an application programming interface (API) to the applications manager.

An operating environment is not a full operating system, but is a form of middleware that rests between the OS and the application. For example, the first version of Microsoft Windows, Windows 1.0, was not a full operating system, but a GUI laid over DOS albeit with an API of its own. Similarly, the IBM U2 system operates on both Unix/Linux and Windows NT. Usually the user interface is text-based or graphical, rather than a command-line interface (e.g., DOS or the Unix shell), which is often the interface of the underlying operating system.

In the mid 1980s, text-based and graphical user interface operating environments surrounded DOS operating systems with a shell that turned the user's display into a menu-oriented "desktop" for selecting and running PC applications. These operating environment systems allow users much of the convenience of integrated software without locking them into a single package.