You run it on the session folder (.win files, usually on ~/.opera/sessions/), and it will generate a single html file with all the bookmarks (taken from the last visited URL for any given tab in that session, hence the file/variable "lasturl" -- the session files record some "history", but this isn't being exported/converted here), and coded "subfolders" for each session file, with the filenames as titles. Every time it runs it rewrites this generated html file....