Comment Re:Good luck not doing that (Score 1) 292
Because Amazon does not publish information about that format, there is exactly one tool that is known to generate this format in a guaranteed forward-compatible way. That tool, kindlegen, was written by Amazon, and the licensing terms from 2.0 onwards (the first version to support nontrivial formatting) do not allow you to use it for creating content that is sold outside Amazon's store. So in order to distribute content elsewhere, you have to either...
Although I haven't used the tool myself, Amazon's description says that "KindleGen is a command line tool which enables publishers to work in an automated environment with a variety of source content including HTML, XHTML or EPUB." So unless there is something more to the licensing terms than you're suggesting, there shouldn't be any problem with creating your content in an open format, and then using KindleGen to generate the content for the Amazon store.