Note:
1) - It will not work on 5.6.x series firmware until someone updates it for that series.
See the Librarian/LibrarianSync thread instead.
6) - Don't even try.
Duokan will not install with **our** jailbreak present - and they haven't stolen and update one of ours for manual installation of the Duokan JB.
It is also unlikely to run unless they specifically state they have a release for 5.6.x series firmware.
It might not run even if they claim it will.