This looks like a possible starting point:
http://fbreader.org/content/fbreader-beta-linux-desktop
Its in Debian, but not (yet) for ARM.
@glimm: Give that application a test run on a lap/desk top machine, let us know if that (on a Kindle) would answer your interests.
Edit: Not exactly a currently maintained project:
https://github.com/geometer/FBReader
But it should be possible to find what project(s) superseded it.
AND Start your own topic thread. This is off-topic for this thread.