The source code for Rocks is available from a public read-only Mercurial repository. As of Rocks 5.0 Mercurial (hg) is installed on your frontend machine, for older version of Rocks (or non-Rocks platforms) you will need to install the Mercurial package yourself. Binary packages for Mercurial are available here.
Mercurial is a distributed source control system. A very good explanation on how this differs from CVS is available on the Mercurial site. Fundamentally, distributed source control turns your checked out source code from a read-only copy into a repository and then grants read-write access to others based on your checked out repository. In the context of Rocks this means individual Roll developers can independently control who has access to their code.
To check out the current source code you will first need to clone the master Rocks read-only repository as follows. This operation will take several minutes (if not hours) and unlike a CVS checkout it may appear to hang, be patient.
$ hg clone http://fyp.rocksclusters.org/hg/rocks-5.3 destination directory: rocks-5.3 real URL is http://fyp.rocksclusters.org/hg/rocks-5.3/ requesting all changes adding changesets adding manifests adding file changes added 1 changesets with 2815 changes to 2815 files 2815 files updated, 0 files merged, 0 files removed, 0 files unresolved