Firefox Weave has become Firefox Sync, and will be part of Firefox 4 in a cloud-based future. Firefox Sync is a server-based store which holds your bookmarks, passwords, preferences and history, providing a consistency of experience that will eventually extend all the way to the iPhone.
The new Firefox cloud Sync is available now as an add-on for Firefox, though a Mozilla blog post explains:
Firefox Sync (formerly Weave Sync) – Currently packaged as a free Firefox Add-on, Sync will be an integrated (opt-in, of course) feature of Firefox 4. It makes your bookmarks, history, Awesome Bar intelligence, passwords, form-fill data and open tabs accessible from Firefox running on other computers and mobile phones. And unlike cloud services that use your data to track your travels throughout the Web for ad targeting or other purposes, Firefox Sync encrypts all of your data before sending it to the server. This means you do not have to sacrifice any privacy or control while still getting the convenience of ubiquitous access to your data using Firefox Sync.
Firefox cloud experience, which will include Firefox Home for the iPhone user who wants to take his bookmarks with him, and a developer’s API for those who want to expand on the functionality. Security is paramount to the point of imposition: connect to the Firefox Synchronisation server and you’ll have to provide a password (of an acceptable length) and a cryptographic phrase which is used to decrypt your details once they’ve been downloaded (only encrypted versions are stored in the cloud). That’s all very commendable, but won’t sit well with the IE crowd, which values simplicity over security.