The TLDR version is Abode supports backward compatibility ... and epub - * International Digital Publishing Forum* - is playing with a sprawling mess opting for the race to the top newest standards ... that always works so well and ensures the user base is always upgrading. I'm very grateful for this information and it explains why I've avoided epub opting for pdf over epub as my reader software is old. I'm am very m…
An epub is just a plain html webpage compressed into a zip and its extension changed from .zip to ".epub". Assuming you have a web browser, you have something that will almost certainly render your epubs contents. PDF is not nearly as pleasant under the hood. It's down right lovecraftian.
PDFs can be painful as well, more often it's then using abode's pdf viewer, but it's far less common for me. There was a time many years ago when I understood PDF structures better, back when I chose to manually edit and fix a couple of malformed PDFs.