One obligatory star Rated 1 out of 5 stars

I agree with all those who give this add-on one star only because it is required. Xmarks was an easy to use and reliable add-on when it was introduced for Firefox 3.x. It vanished because it couldn't be maintained and it re-appeared in this horribly unreliable version. One time it sync'd my bookmarks to oblivion and on another occasion scrambled completely scrambled them. At least the backup worked... So long, Xmarks.