Excellent visuals, uses Artificial Intelligence to help you organize and located your saved bookmarks.
Pros (cont'd): I am using it with Opera also. (I found buttons at BookmarkOS, while using Opera, that I could move onto the Opera bar.)
Cons (cont'd): The Firefox extension giving access to the BookmarkOS desktop opens a fixed window that is too small for my preference. I removed the extension from Firefox and made the BookmarkOS desktop my homepage in Firefox. (I got rid of the extraneous, intermediate, "bookmarks" folder from the upload.) The folder names start with whole numbers that order them and ahead of them come a few individual, much-used bookmarks (like Google Advanced Search) with names starting with, for example, 0.1 to put them ahead of the folders, just where I want them.