The subversion tree contains the sources and some example applications. You can browse it online on http://svn.mech.kuleuven.be/websvn/orocos

The main line can be found here:

svn co http://svn.mech.kuleuven.be/repos/orocos/trunk/rtt

The RTT branches can be found here:

svn co http://svn.mech.kuleuven.be/repos/orocos/branches/rtt/

For example, for the 1.10 release, you use:

svn co http://svn.mech.kuleuven.be/repos/orocos/branches/rtt/rtt-1.10

Installation instructions can be found in the documentation section.