Firefox bookmarks
Firefox bookmarks originally used the HTML-based Netscape bookmarks format, as did the Mozilla/Seamonkey Suite. However, as of Firefox 3.0, a new format was used based on SQLite with write-ahead logging. The bookmarks are also regularly automatically backed up in the JSON format.
The relevant files are places.sqlite and places.sqlite-wal in the user profile directory (system-specific; in Windows Vista and 7 it is \Users\username\AppData\Roaming\Mozilla\Firefox\Profiles\cryptic-profile-ID). This directory structure may be hidden depending on your operating system configuration. A subdirectory of this called bookmarkbackups has the backups, with filenames like bookmarks-2012-10-28.json which contain the date of the backup.
The data structure in the SQLite file is given in the embedded commands:
CREATE TABLE moz_bookmarks (id INTEGER PRIMARY KEY,type INTEGER, fk INTEGER DEFAULT NULL, parent INTEGER, position INTEGER, title LONGVARCHAR, keyword_id INTEGER, folder_type TEXT, dateAdded INTEGER, lastModified INTEGER, guid TEXT)
CREATE TABLE moz_bookmarks_roots (root_name VARCHAR(16) UNIQUE, folder_id INTEGER)
CREATE TABLE moz_keywords (id INTEGER PRIMARY KEY AUTOINCREMENT, keyword TEXT UNIQUE)
CREATE TABLE sqlite_sequence(name,seq)
CREATE TABLE moz_favicons (id INTEGER PRIMARY KEY, url LONGVARCHAR UNIQUE, data BLOB, mime_type VARCHAR(32), expiration LONG, guid TEXT)
CREATE TABLE moz_annos (id INTEGER PRIMARY KEY,place_id INTEGER NOT NULL,anno_attribute_id INTEGER,mime_type VARCHAR(32) DEFAULT NULL,content LONGVARCHAR, flags INTEGER DEFAULT 0,expiration INTEGER DEFAULT 0,type INTEGER DEFAULT 0,dateAdded INTEGER DEFAULT 0,lastModified INTEGER DEFAULT 0)
CREATE TABLE moz_anno_attributes (id INTEGER PRIMARY KEY,name VARCHAR(32) UNIQUE NOT NULL)
CREATE TABLE moz_items_annos (id INTEGER PRIMARY KEY,item_id INTEGER NOT NULL,anno_attribute_id INTEGER,mime_type VARCHAR(32) DEFAULT NULL,content LONGVARCHAR, flags INTEGER DEFAULT 0,expiration INTEGER DEFAULT 0,type INTEGER DEFAULT 0,dateAdded INTEGER DEFAULT 0,lastModified INTEGER DEFAULT 0)
CREATE TABLE moz_places (id INTEGER PRIMARY KEY, url LONGVARCHAR, title LONGVARCHAR, rev_host LONGVARCHAR, visit_count INTEGER DEFAULT 0, hidden INTEGER DEFAULT 0 NOT NULL, typed INTEGER DEFAULT 0 NOT NULL, favicon_id INTEGER, frecency INTEGER DEFAULT -1 NOT NULL, last_visit_date INTEGER, guid TEXT)
CREATE TABLE moz_historyvisits (id INTEGER PRIMARY KEY, from_visit INTEGER, place_id INTEGER, visit_date INTEGER, visit_type INTEGER, session INTEGER)
CREATE TABLE moz_inputhistory (place_id INTEGER NOT NULL, input LONGVARCHAR NOT NULL, use_count INTEGER, PRIMARY KEY (place_id, input))
CREATE TABLE sqlite_stat1(tbl,idx,stat)
CREATE TABLE moz_hosts ( id INTEGER PRIMARY KEY, host TEXT NOT NULL UNIQUE, frecency INTEGER, typed NOT NULL DEFAULT 0, prefix)