A2 (operating system)
Bluebottle OS, AOS
A2 (formerly named Active Object System (AOS), and then Bluebottle) 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 (TUI) with a zooming user interface (ZUI), which is similar to a conventional graphical user interface (GUI). 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 (OOP) model of an object, combined with a thread that executes in the context of that object.
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