Years ago When I dual booted with Windows NT4 and various Linux distros I used Firefox in both operating systems. I used a common approach for sharing a profile between two operating systems by using a common FAT32 partition. I have no recollection about how I resolved forward and back slashes in file paths. Regardless, I stopped sharing a common profile when I stopped dual booting with Windows.
Fast forward years later and I again face the same basic challenge of sharing Firefox settings among multiple physical computers and user accounts.
A lack of “roaming profile” support affects most Linux based apps. The design of almost all apps is user-centric, expecting to be stored and maintained in the user’s $HOME directory. Few apps are designed to store settings outside that location.
Primarily I use an office desktop and a Thinkpad T400 laptop. For a long time I have used multiple distros on the laptop. While for many years now I have used only one distro on the desktop, I plan to expand to some others. I use different user accounts in each environment. I use common apps, including Firefox.
There are times when I wish I could move from one system or distro to another and continue my browsing session.
Some digging and reflection indicates a common profile much like my dual booting days might suffice. I need a central location for the profile. Second, I need to sync that central location to my laptop when I use the laptop away from my home network.
Using a networked /home mount point is one way to resolve the problem. Sym links would be another solution. Either way some challenges remain.
One, neither approach supports concurrent usage. Sometimes I start using Firefox on one computer and then continue with another computer. I need to always fully close Firefox before roaming because with Firefox, the location that last closes Firefox is the one that updates the profile files.
For example, when I open Firefox at my desktop, leave Firefox running, move to my laptop, modify my bookmarks, close Firefox at the laptop, and then close Firefox at the desktop, I will lose the bookmark change.
Second, I use the NoSquint add-on. Because of different screen sizes, the settings I use for any particular web site are different between the desktop and laptop.
Third, I use different font sizes between the two environments.
Then there is the challenge of different Firefox versions. For example, CentOS use the ESR version, which except for a few weeks every year is always different from my other distro installs. Different versions affects a few prefs.js settings.
Another option is exploring the use of Firefox profiles. Use one profile when using the laptop and another when using the desktop. Firefox supports explicit file paths for profile locations rather than relative paths.
Firefox is not well designed for roaming users or concurrent usage.