Mozilla’s open-sourced sync engine Weave has finally hit version 1.0. This killer add-on automagically keeps any number of authorized computers and mobile devices running Firefox up-to-date. It’s like having your Internet life in perfect sync, wherever you go.

After dozens of pre-releases and betas, Mozilla’s syncing add-on for Firefox is finally ready for prime time. The non-profit organization pitched Weave as a way to “securely access all of your personal data across all of your supported devices, making your web experience instantly more personal and useful.” Syncing your Internet life with Weave is a peace of cake. Upon Weave 1.0 addon installation, you are asked to register for a free account on Mozilla’s server where all your information is stored securely in an encrypted database. Choose your username, password, and secret phrase and you’re ready to go.

Weave options are accessed via Tools > Weave or an icon sitting in Firefox’s bottom right status bar. You can choose to sync everything (recommended) or custom-pick the supported items, currently bookmarks, passwords, history, open browser tabs, and Firefox’s preferences. Weave currently syncs only your 25 most recently used tabs and puts them under the Firefox’s “Tabs From Other Computers” item in the History menu.

With Weave active on your machine, you never have to worry about manually backing up aforementioned items. This will be indispensable comes when re-installing your system or moving to a new machine. Simply run Weave on your new machine and lay back as it automagically populates saved Firefox items. Be careful, though, because any changes you make to the synced items instantly get carried over to all linked computers. Fortunately, Weave creates a backup of your bookmarks before any drastic actions, such as full bookmark deletion by choosing to Start Over. Clearing your private Firefox data via Tools > Clear Recent History will cause Weave not to sync those changes, meaning the deleted entries will not be in sync between computers.

Weave doesn’t sync your master Firefox password. If you use a master password on your desktop but not on your mobile phone, then your passwords will not be protected with your master password on your mobile phone. If you use a master password, Weave will automatically sync with the cloud after you enter in your master password. In addition, Weave stays disconnected until you enter your master password again or manually connect. In order to improve performance and bandwidth use, Weave syncs data in chunks.

For example, up to a thousand history items are uploaded to the cloud during the initial sync (bookmarks are also synced in chunks). Any remaining items will be synced in subsequent sync attempts and may cause your bookmarks to appear unsorted, but this will resolve once all the items get uploaded. Note that the initial sync may take anywhere between a few minutes to up to an hour to complete, depending on the size and breadth of your browsing environment.

When Weave completes the initial sync, any actions you perform – like adding or deleting bookmarks, visiting sites, or entering new passwords – will be synced quickly because only the changed data is sent to the server. If you want to reset sync data, choosing Start Over will let you replace whatever data is on your machine with server data, merge your computer’s data with the Weave server, or replace all other devices with your local data.

Being a 1.0 version, Weave isn’t without a few hiccups. For example, syncing a Weave device that has been inactive for a while may cause your current data to be overwritten by stale data from that device. Luckily, there’s a workaround: Simply perform a Start Over when you’re connecting a really stale device and choose to replace the local data with most recent data from the Weave server.

Also bear in mind that favicons for your bookmarks are currently not synced to the server so if you bookmark a site on your home computer, don’t expect its favicon to show up on your work machine. Finally, folks running mobile Firefox on Maemo devices like the Nokia N900 should first upgrade their desktop to Weave 1.0 to avoid stalling mobile Firefox to a halt because the initial sync can be pretty demanding.

The real beauty of Weave is its open architecture that will make adding new data types a breeze. Mozilla has opened up Weave to add-on developers so you’ll be soon able to sync settings and information from your favorite third-party add-ons as well. Mozilla also said that Weave will soon support Personas, add-ons, search plugins and about:config tweaks, allowing you to fully synchronize your browsing environment in its entirety.

I don’t know about you, but I’ve been struggling to keep tabs on my bookmarks and passwords prior to Weave. I actually used to back up local browsing items on a USB drive, but it’s been such a terribly frustrating experience. Needles to say, just as I’d stopped doing back ups on a regular basis, my machine died on me. I also once reinstalled Windows without remembering to backup Firefox data first. With Weave, I can just fogeddabout it! When I get myself a mobile device capable of running mobile Firefox, I’ll just run Weave to have my mobile experience automatically customized according to my desktop settings.

Conclusion: You shouldn’t live without it

Wouldn’t you like to have open web sites on your desktop instantly available on your mobile device? Check. Easily sign in to all your favorite sites using your saved passwords, which is really handy on your phone where it’s hard to type in complex passwords? Done. Get the same results on the Smart Location Bar on each of your Firefox browsers, so you can get to your favorite sites with just a few keystrokes? That too. How could you have ever lived without Weave?

You can download Mozilla Weave 1.0 for desktop or mobile Firefox here. The open source organization warned users to make sure they download and install the Weave 1.0 add-on from addons.mozilla.org on all the devices they want to sync in case they have been installing previous Weave versions from other places. More information about Weave is available in the official release notes and on the Mozilla blog.