Rapsodia is an open source project and is released under the LGPL v2.1. The sources can be obtained either via the source repository or by downloading the latest tar ball.

As a tar ball:
The latest tar ball is based on mercurial tag "f65927e3ce9b tip ", can be downloaded as

Rapsodia_2014-03-05 .tgz

and was created on 2014-03-05

From the repository:
For version control we chose the mercurial system. One can browse the source code (Rapsodia) and browse example setups (RapsodiaExamples) repositories which are accessible (read only) from Argonne's server. Assuming mercurial is installed on the user's machine, the source repository can be copied (cloned) with the following command:
hg clone http://mercurial.mcs.anl.gov/ad/Rapsodia
Subsequent updates can be incrementally downloaded and applied by running  (the URL part may be omitted if mercurial is configured to remember the clone location) 
hg pull http://mercurial.mcs.anl.gov/ad/Rapsodia
hg update

To obtain the examples repository simply replace Rapsodia with RapsodiaExamples in the above commands.

Contribute to  the source repository using mercurial:
Because the repository mentioned above is read access only, external contributions have to be submitted as bundles. Assuming you made a change in your local repository and created a changeset
by  committing the change (see the mercurial wiki) you cannot directly push that change onto the server. Instead you can create a bundle
hg bundle <file_name_of_the_bundle> http://mercurial.mcs.anl.gov/ad/Rapsodia
and then send the resulting file by e-mail. We can then evaluate the changes and apply them to the main repository.