Since FF 2.0 there has been a session manager available on the Tools menu that stored a number of backup sessions ordered by date and time. I note that other people are looking for it since FF version 29 was introduced. I use the Tab Mix Plus add on which has the facility to open only the previous session. However it asks quite clearly in the options "do you want to use the built in Firefox Session Manager" but if you choose to use the built in session manager... nothing appears on the Tools Menu to allow you to use it. Will you be reinstating this very useful. part of FF and when will it be available? Thanks