A big milestone here in viewing well-formed, nbformat-validated Jupyter Notebooks in their native JSON format:
This is powered by the excellent nbdime, mentioned a bit above, with the longer history of this effort here:
Because it’s powered by an actual Jupyter tool, and not an intern’s copy in the platform’s language du jour, it works for every version of the Jupyter Notebook Format, even those from before The Big Split.
And while of course, this is on a proprietary platform, of course owned by a Big Tech of consistently dubious morals, as a community we can at least bask in being embraced for a while 
.