Session Manager 0.6.4.6 is a Browser Plug-Ins product from sessionmanager.mozdev.org, get 4 Stars SoftSea Rating, Session Manager saves and restores the state of all windows - either when you want it or automatically at startup and after crashes. Additionally Session Manager offers you to reopen (accidentally) closed windows and tabs. If you're afraid of losing data while browsing - this extension allows you to relax.
Building upon SessionStore, this extension allows you to save the current state of Firefox (history, text data, cookies) and return to that state at any later moment. Besides the manually saved states, Session Manager automatically stores the current state in case of a crash.
All sessions are stored in the "sessions" folder inside your profile directory and can be moved around as any other file. To get to that folder, simply select "Open Session Folder" in Session Manager's menu (might not work on all OSes). Finally, Session Manager also allows to reopen the 10 last closed windows and tabs.
It is not recommended to use Session Manager at the same time as SessionSaver or Tab Mix Plus's Session Manager feature (*) (which provide similar functionality on their own). In comparison, Session Manager currently stores more session data than Tab Mix Plus while not getting as complex as SessionSaver. Session Manager can import existing sessions from both Tab Mix Plus and SessionSaver.
(*) - Session Manager may be run with Tab Mix Plus, as long as Tab Mix Plus's built in Session Manager and Crash Recovery are not enabled. In Firefox 3, Tab Mix Plus automatically detects when Session Manager is installed and disables its own Session Management functionalty. The license of this internet software is Free Trial Software, you can free download and get a free trial before you buy. If you want to get a full or nolimited version of Session Manager, you can buy this internet software.