New version of Kindle for PC

[DiapDealer]

Originally Posted by JSWolf

I thought AZW3 had both KF8/Mobi inside and the same file could be read on any Kindle.

No. Only the output of Kindlegen (and the experimental calibre tweak) produces the combination MOBI/KF8 files. That's what gets uploaded to Amazon by the publisher/e-book creator. Amazon is not delivering those combo files to any customers. The customer gets a regular old Amazon MOBI/AZW if their device/app can't handle KF8 (or if the ebook wasn't created with KF8 support). If their device can handle KF8 (and KF8 is available), they get a stand-alone(ish) KF8 file (which may—but certainly doesn't have to—be named with an AZW3 extension.

I repeat ... no combination MOBI/KF8 files are being delivered to customer devices/apps by Amazon. It's either/or depending on the device/app's capabilities.

EDIT: However... a combination file built by kindlegen is readable on any Amazon device/app if you would happen to distribute one yourself.