I have Firefox installed on three separate computers, and I find it difficult to keep the same Add Ons/Preferences synchronised between all three machines. Is there an automated way to synchronise my Firefox installation between all three machines? In other words, if I add a new Add-on or Greasemonkey script to one Firefox installation, can it be automatically added to my installation on my two other machines?
Three Firefoxes, One User
This has been the holy grail of Firefox needs since Firefox extensibility turned us all into tweaking junkies. You can already use tools like Foxmarks or Mozilla Weave to sync bookmarks, passwords, and a little bit more (with Weave), but unfortunately there are no tools built specifically for syncing your extensions in the same seamless manner. So what's a Firefox lover to do?
As it turns out, there are several ways you can go about syncing Firefox so that you've got the exact same browser—history, extension, bookmarks, passwords, and all—no matter where you're working.
Option 1: Go Portable
Probably the easiest option is to download Portable Firefox, toss it on your thumb drive, and take it with you everywhere you go. It's not syncing, of course, but it is guaranteed to work without any significant effort on your part aside from carrying around a thumb drive.
Option 2: Sync Portable
You can take the portable idea one step further with free syncing tools like Dropbox. Just download and install Dropbox on every computer you want to sync Firefox to, then download Portable Firefox and store it in your Dropbox folder. Dropbox will automatically sync to Portable Firefox to the Dropbox folders on your other computers.
Since the whole point of Portable Firefox is that it can live anywhere, and it doesn't require any specific folders outside of itself, every change you make on one computer should automatically sync to all of your other Portable Firefox installs on the rest of your computers. As long as you aren't using Firefox on two computers at the same time, everything should run flawlessly. With two Portable Firefoxes running simultaneously, you may run into the occasional conflict—though even then it's rarely a major problem.
Finally, since Dropbox syncs to the web as well as your desktop, this setup as two more benefits. First, both computers don't need to be running at the same time to perform the sync. Instead, whenever one computer turns on, it'll automatically sync up to the latest version from the web. Second, if you're ever at a computer that isn't yours, you can navigate to the Dropbox web interface and download your customised Portable Firefox to any computer. That way you can have your perfectly personalised browser no matter where you are, then delete it when you're done.
Option 3: Sync Application Data
If the Portable Firefox route doesn't appeal to you, you can still sync Firefox installations—extensions and all—by syncing your application data with FolderShare or a similar syncing tool. (Dropbox isn't ideal for this one because it doesn't let you choose multiple folders anywhere on your desktop to sync, while FolderShare does.) I've walked step by step through this process in detail once before, so I won't go into it here.
Like the Dropbox version above, you may see the occasional conflict if you sync Firefox this way.
I hope that helps, TFOU. It's still not perfect, and we're all waiting patiently for the day that one Firefox extension takes care of all our browser syncing needs, but in the meantime, one of these methods should do. If anyone has other suggestions for how they keep their Firefox installations in sync, let's hear them in the comments.