Did anyone else find the story about switching from a tree structure to a list kind of weird? On the one hand, that's a pretty trivial sort of optimization, and hardly seems worth making a fuss about.

But on the other hand, isn't he assuming that any future users of his compiler will have source code that looks like his? Sounds like all it would take is one person using an automatic code generator to generate Oberon code that's not smart about reusing variable names to bring the compiler to its knees...