From Renaissance Security

Just like Firefox 3, Firefox 4 stores the browser history in an SQLite database. For Windows Vista/7, it’s located at :\Users\\AppData\Roaming\Mozilla\Firefox\Profiles\\places.sqlite This database contains the tables moz_anno_attributes moz_annos moz_bookmarks moz_bookmarks_roots moz_favicons moz_historyvisits moz_inputhistory moz_items_annos moz_keywords and moz_places These tables seem unchanged from version 3, as documented on the MozillaZine.