A2 (operating system)
A2 is a modular, object-oriented operating system with features including automatic garbage-collected memory management, and a zooming user interface. It was developed originally at ETH Zurich in 2002. It is free and open-source software under a BSD-like license.
History
A2 is a successor to Native Oberon, the x86 PC version of Niklaus Wirth's operating system Oberon. It supports multiprocessing computers, and provides soft real-time computing operation. It is entirely written in Active Oberon.User interface
Bluebottle replaced the older Oberon OS's unique text-based user interface with a zooming user interface, which is similar to a conventional graphical user interface. Like Oberon, though, its user interface supports a point and click interface metaphor to execute commands directly from text, similar to clicking hyperlinks in a web browser.Features
A2's design allows developing efficient systems based on active objects which run directly on hardware, with no mediating interpreter or virtual machine. Active objects represent a combination of the traditional object-oriented programming model of an object, combined with a thread that executes in the context of that object. In the Active Oberon implementation, an active object may include activity of its own, and of its ancestor objects.A2 incorporates a minimalist design, implemented in a type-safe language with automatic memory management, combined with a set of primitives for synchronizing access to the internal properties of objects in competing execution contexts.
Above the kernel layer, A2 provides a set of modules providing unified abstractions for devices and services, such as file systems, user interfaces, computer network connections, media codecs, etc.