3 ms·

What’s the significance of dropping MOBI? I generally only hear of ebooks released as ePubs, although Ive seen MOBI files around.

JKCalhoun 5y ago
I suppose the significance is that there is now only one other competitor to Amazon's format?
derefr 5y ago
MOBI is, and always has been, the format used by Kindle eBooks. (Amazon bought the creator of the format, MobiPocket, in 2005, shortly before launching Kindle.) The prevalence of MOBI files today is mostly down to people ripping purchased Kindle books off their devices and releasing them to piracy. The current file format for Kindle purchases, AZW, is just MOBI + DRM. If you strip out the DRM / customer fingerprint, you’re left with a MOBI file. So a large percentage of ripped books on e.g. LibGen will be in MOBI, even though the source was AZW. You can’t remove the identifying fingerprint of the purchaser without also removing the DRM entirely; so pirates do both. The significance here is essentially that Kindle apps/devices will no longer willingly import+load+display pirated books originally ripped from the Kindle store. Because, at this point, that’s what 99.9% of MOBI files are.
- davidgerard 5y ago
  Quite a lot of AZW are really ePub inside. Kindle accepts ePub just fine. This means self-publishers will often just do an ePub, because that gets them onto everything without extra work.
- jasonvorhe 5y ago
  But this announcement only applies to publishing. Taking a mobi from Libgen and sending it to my Kindle via mail shouldn't be affected at all by this?
  - stonecharioteer 5y ago
    Or copy via USB?
- jscholes 5y ago
  > The current file format for Kindle purchases, AZW, is just MOBI + DRM. Not these days it isn't. They built a custom format to support additional features some time ago, KFX[1]. [1] https://wiki.mobileread.com/wiki/KFX https://wiki.mobileread.com/wiki/KFX

JKCalhoun 5y ago

I suppose the significance is that there is now only one other competitor to Amazon's format?

derefr 5y ago

MOBI is, and always has been, the format used by Kindle eBooks. (Amazon bought the creator of the format, MobiPocket, in 2005, shortly before launching Kindle.) The prevalence of MOBI files today is mostly down to people ripping purchased Kindle books off their devices and releasing them to piracy. The current file format for Kindle purchases, AZW, is just MOBI + DRM. If you strip out the DRM / customer fingerprint, you’re left with a MOBI file. So a large percentage of ripped books on e.g. LibGen will be in MOBI, even though the source was AZW. You can’t remove the identifying fingerprint of the purchaser without also removing the DRM entirely; so pirates do both. The significance here is essentially that Kindle apps/devices will no longer willingly import+load+display pirated books originally ripped from the Kindle store. Because, at this point, that’s what 99.9% of MOBI files are.

davidgerard 5y ago
Quite a lot of AZW are really ePub inside. Kindle accepts ePub just fine. This means self-publishers will often just do an ePub, because that gets them onto everything without extra work.
jasonvorhe 5y ago
But this announcement only applies to publishing. Taking a mobi from Libgen and sending it to my Kindle via mail shouldn't be affected at all by this?
- stonecharioteer 5y ago
  Or copy via USB?
jscholes 5y ago
> The current file format for Kindle purchases, AZW, is just MOBI + DRM. Not these days it isn't. They built a custom format to support additional features some time ago, KFX[1]. [1] https://wiki.mobileread.com/wiki/KFX https://wiki.mobileread.com/wiki/KFX