When you work on a project, usually you have lots of tabs open in Firefox: some Google results, related blog posts, API documentations, etc. If you use several machines, it would be useful to save the current tab list to a file, and restore the list on another machine and continue the work from where you stopped.
Save the current tab list
What you need is the URL Lister Firefox add-on (official home page is here). Once installed, go to Tools -> URL Lister…, copy the list to the clipboard and save it to a file, send it to you in e-mail, etc.
Restore the tab list
For restoring the tab list, use the script open_in_tabs.py. Example:
cat url_list.txt | ./open_in_tabs.py
You are working on a (hobby) project on your desktop machine. You feel like going to the library where you want to continue the project on your laptop. Just save the tab list and open the very same tabs on your laptop.
If you need to restart Firefox and/or your machine, you can ask Firefox to restore your tab list. Go to Edit -> Preferences -> General tab, and next to “When Firefox starts“, select “Show my windows and tabs from last time“.
You make some research on a topic and you have several tabs opened in Firefox. You have to close the browser but upon the next start you would like to get back the tabs to continue the work. How to do that?
To restore the previously opened tab list, you don’t need any specific add-on. This possibility exists in Firefox. Here is what you need to do: go to Edit -> Preferences, and choose the General tab. Here you have a dropdown list on the top that says “When Firefox starts“. Choose “Show my windows and tabs from last time“, then Close. That’s all.