You can check out the latest unstable release of Tracker using git.
$ git clone git://git.gnome.org/tracker
If you plan on pushing changes back upstream and have a GNOME account, use the following instead:
$ git clone ssh://<username>@git.gnome.org/git/tracker
For more information on this, see the instructions on how to use the repository
There are no unstable releases since the last 0.16 release series were done. We will be starting 0.17 releases soon.
Check out the latest stable releases of Tracker 0.16.