Wirth is one of my biggest influences. I was just inspired by this post to finish a short little draft I had sitting around about Wirth as an influence, and the Oberon language report. Oberon-07 is defined in a 17 page document that is simplicity itself. Of that, about 2 pages is EBNF (Wirth published the first EBNF variation too...) for Oberon, and the rest is easily accessible prose...

Unlike most languages, Wirth's languages have gotten simpler, but more powerful, from generation to generation. His greatest legacy to me is his focus on engineering vs. science in programming language design. He's never been concerned with adding the latest and greatest features, but on what is proven, and what has a well understood means of efficient implementation.

This is both the beauty and elegance of his language designs, and in some ways probably his "downfall" in terms of getting credit outside of quite small circles:

Wirths languages are not "sexy". They're stripped down and bare. Their implementations are not sexy - they're stripped down and bare: Simple recursive descent parsers with direct code generation (most, or possibly all, of his compiler implementations output code without generating an AST at all) and minimal optimization - focusing on being easy to understand and modify, predictable, and fast, rather than on producing the fastest possible code.

But that's what makes him stand out as a beacon of programming language engineering. We need the fancy, sexy languages and implementations too, but "Wirthian" languages and compilers are an important counterpoint.

(The blog post is here: http://www.hokstad.com/oberon)