@
AndrewH,
Everything you said, I am aware of. And I gave the Cliff's Notes version in this thread.
Rewriting the world in a different programming language is not a viable goal.
That is why ChromeOS is still a toy outside the browser.
"But technically..."

If you want to feel insulted about people recomending Windows/Linux
on the ground that no current ChromeApp fulfills their need, just imagine how insulted
I feel when you: claim I am insulting you, then proceed to declare that really, ChromeOS is exactly what the OP needs, and it is merely a side point that "technically", no one has written a JS-based calibre port.
And all I said was that you'll need to get into developer mode and activate Crouton if you want to run python programs on ChromeOS.