This is addressed in the abstract of the paper: > But ever since Pascal, the language aspect has been almost secondary to Wirth's work. Modula(-2) and Oberon b

This is addressed in the abstract of the paper: > But ever since Pascal, the language aspect has been almost secondary to Wirth's work. Modula(-2) and Oberon both came out of larger system-level design projects that simultaneously also developed workstation computers, modular operating systems, and suites of innovative application programs. Unfortunately, these other important contributions were overshadowed by the programming languages they were associated with, and hence never received the recognition they deserved. Oberon was both a programming language and an operating system implemented in that programming language. Much like LISP machines, the boundary between programming language and operating system is fuzzy.