Oberon plus classes and methods by H. MoeSSEnboeck & J. Templ, 1989. See Oberon-2. ["Object Oberon - An Object-Oriented Extension of Oberon", H. MoeSSEnboeck et al, ETH TR 109 (Apr 1990)]. ["Object Oberon - A Modest Object-Oriented Language", H. MoeSSEnboeck & J. Templ, in Structured Programming 10(4), 1989].