Differences between Mathematica 5 .. 12 (and different flavors)

[rocky]

Document or describe the different flavors of Mathematica? (InputForm/FullForm dimension, notebook/cloud/.. platform)
In particular what's changed between releases. As an example for something similar, be See Section 4 page 166 of http://rocky.github.io/elisp-bytecode.pdf

Ideally, variants of the grammar would exist. I just googled to see if ANTL4 has includes. Not directly, but see https://stackoverflow.com/questions/56289605/how-to-implement-include-files-in-antlr/63280459#63280459