The subversion tree contains the sources and some examples.

The main line can be found here:

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


The 0.6 branch can be found here:

svn co http://svn.mech.kuleuven.be/repos/orocos/branches/bfl/branch-0.6


Installation instructions and a getting started guide can be found in the documentation section.