http://plone.org/development/info/participation
I wanted to took part in plone development (though I am a novice)
thats why tried to get the code as described in the link and install.
That is a good tutorial to use for any svn code download and install for plone.
Setup a fresh Zope instance with all dependencies for PsARAAS:
$ svn co https://svn.siteurl.com/path foldername
$ cd foldername
$ python bootstrap.py
$ bin/buildout
Start the zope instance:
$ bin/instance fg