Active Oberon is a general purpose programming language developed during 1996-1998 by the group around Niklaus Wirth and Jürg Gutknecht at the Swiss Federal Institute of Technology in Zürich (ETH Zurich). It is an extension of the programming language Oberon. The extensions aim at implementing active objects as expressions for parallelism. Compared to its predecessors, Oberon and Oberon-2, Active Oberon adds objects (with object-centered access protection and local activity control), system-guarded assertions, preemptive priority scheduling and a changed syntax for methods (named type-bound procedures in Oberon vocabulary). Objects may be active, which means that they may be threads or processes. The operating system named Active Object System (AOS) in 2002, then due to trademark issues, r