The "trunk" series represents the primary line of development rather than a stable release branch. This is sometimes also called MAIN or HEAD.
14.04's version of the Ubuntu online tour.
This is the 13.10 version of tour.
The series and branch for the Raring Ringtail (13.04) version of Ubuntu online tour
Update to represent 12.10
This is the 12.04 version of tour.
Extended tour for packaging