Now there’s a way to convert native ODF documents, thanks to HanoiLUG volunteer JC you can now convert document from ABC and VNI font to unicode. It’s still a command line tool, but it is very easy to use. More information on here http://www.hanoilug.org/dokuwiki/projects:ovniconv.
If you are a Ubuntu user you can get it by using hanoilug repository.
We are looking for someone to package it for Fedora and other distribution. It would also be nice to have someone who can take care of the Fedora repository.