The Mozilla Labs Weave project has been changing quite a bit in the recent past. Here are some quick links to get you to where you want to goWeave Sync is now called [[Firefox Sync]].
If you are looking for information about the Firefox Sync feature, go [httphttps://www.mozillamozillalabs.com/en-US/firefoxsync/sync here].
If you are looking for information about the various Online Identity related projects, go [https://mozillalabs.com/conceptseries/identity/ here].