I have been following the development of Oberon-07 (and submitted minor fixes to Prof. Wirth) over the years. The compiler's source code is the fruit of refinements and simplifications accumulated over 30+ years (more if you include his compilers for previous languages). His approach for compiler writing, and system design in general, is outstanding. For more information about his compilers see "Compiler Construction - The Art of Niklaus Wirth" [0]

[0] http://oberon2005.oberoncore.ru/paper/art3.pdf

Still coding at age 84. Good for him!

I got to meet him at CERN back when Oberon was still being pushed by ETHZ and Oberon microsystems.

It was a very nice experience interacting with him.

is there any github mirror of this code base?

Oberon is well worth studying. If you're on macOS, you can get it via the App Store (it's free).

As far as github mirrors, I'm not sure there is one. But this looks interesting: https://github.com/Spirit-of-Oberon/ProjectOberon2013

But you may just want to get the original code and read through the books at http://www.projectoberon.com/

Can’t find it in the App Store. Can you link to it?

Sure! https://itunes.apple.com/us/app/oberon-workstation/id1057155...

NICE!! Cannot wait to use it.

If you are interested in the Oberon-07 language, I made a port of Wirth's compiler for the JVM, see [0]. Several other implementations exist for different platforms [1].

[0] https://github.com/lboasso/oberonc

[1] http://oberon07.com/compilers.xhtml