Recently Adrien Bustany blogged about the Firefox extension for Tracker and has yet to blog about his Thunderbird extension work.
As you would expect, the Firefox extension syncs bookmarks to Tracker (in that direction only for now) and the Thunderbird extension sends email to Tracker to be indexed (even full text content of emails which our Evolution miner doesn’t do because of the system stress it causes). This is really quite superb work from Adrien and tracker-needle already supports bookmarks and emails so it all just works after a make install (into the $prefix where Firefox/Thunderbird are installed). Currently the Thunderbird extension requires version >= 5.0 (works with betas too), and the Firefox extension requires version >= 4.0 (and supports 5.0).
These works have been imported using a pretty cool tool after I felt more comfortable using that to import Adrien’s subtrees into Tracker’s git repository. I did read up on the coolest merge ever from Linus but it felt more like a hack to me to do it that way. Still, I guess Linus knows what he is doing 
So now we have both plugins imported with full history into git. The thunderbird branch was merged to master today and the firefox branch will be merged this week hopefully pending Adrien’s review. Great stuff!
Source: My blog