Rated 5 out of 5 stars
Five stars are hardly enough to describe the usefulness of this extension. If you write e.mails on more than one computer, it's a must-have!
Ever missed an appointment because you forgot that you entered it only on the other computer?
Fed up with taking care of two address books in parallel? Get this extension and have more fun in life! :)
I have version 1.0.0 running with Thunderbird 1.5 and 2.0. After the first sync, nothing is overwritten, you will see all entries on all machines. After deleting the double ones, you are set!
As already said, I can only recommend this extension. I did not lose contacts, no appointments disappeared -- Sync Kolab does what it is supposed to do, reliably!