Firefox always had good bookmark management features. The Bookmark Manager (Library) had features like Export Bookmarks to HTML. You could easily create periodic copies of your bookmarks and keep them as backups. Syncing them to online bookmark tools like Xmarks also helps to keep your bookmarks for posterity.
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Firefox 13 has added another feature to your bookmarks toolbar which gives you additional control if you think you have deleted a bookmark by mistake. Now, you can easily recover your bookmarks by date. Firefox now automatically backs up and keeps a copy of your bookmarks going back in time to the tenth day from the current date. Click on Bookmarks – Show All Bookmarks.
The Library window gives you the Import and Backup menu. The dropdown reveals the Backup feature and the new Restore function.
So, let’s say you lost a bookmark day before yesterday. You can jump a day before that to reclaim and recover the lost bookmark. You can even go incrementally day by day into the past (but not beyond 10 days) to recover the bookmark in Firefox. Selecting a specific date backs up the entire set of bookmarks with an exact copy of bookmarks as was automatically bookmarked by Firefox on that date. Click on OK to revert your bookmarks to the old copy.
Is there a way to increase or decrease the limit of ten? I haven’t figured that out yet; if you have drop the tip in the comments.