Here is my problem: I have to use many different computers every day. I use several laptops and desktops running Linux, Mac, and sometime even Windows. The good news is that I have Firefox on all of these machines, and have been using sync to pass along my tabs. However, after using sync for several months, I have to say the current interface just does not cut it for a tab junkie like me. I have *hundreds* of tabs open and recently I have started using tab groups as a way of organizing them. Sync does not seem to transfer my tab groups metadata, it just transfers the tabs. All of my tabs become available in a list without the group info which is not ideal when you have hundreds of tabs. What I really want is a solution that would sync my tabs and groups exactly as they are and where they are and as soon as I open, move, or close them from any system. I am only one person so normally I only operate one computer at a time. When I move from one Firefox to another, I want to see exactly what I was seeing when I used it last, regardless of where I was last. I don't want to do extra work to find and open my tabs and organize them in groups in each machine that I use -- all this metadata should just automatically transfer. I have heard that there are some third party apps like Xmarks, but honestly I am a bit worried about using those kind of solutions. I don't want to give my data to them, especially if the software they are using is not free and open source. To reiterate my question again, I am looking for a free and open source solution to immediately and automatically sync any changes to tabs and groups across all of my Firefox instances. Is there any solution that would allow me to use Firefox in this way?