Checking Out from the Contributions Repository
The Contributions repository is a separate CVS area from the main core code repository. It is used for third-party modules, themes, translations, etc. If you've heard the phrase "contrib module", this is the place where they get stored. See the Contributions FAQ and the README.txt for more information.
Just like the main repository, anyone can browse the contributions repository anonymously via the cvs web interface. Anonymous users can also check out individual modules or themes via the command line:
Checking out the latest contrib projects
To get the most recent modules, themes, or translations, cd your way to the root of the drupal install for which you wish to update a project, and run the command:
// Checkout one project at a time:
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout contributions/modules/name_of_contrib_moduleThe -z6 switch enables compression during the download. The
-d switch indicates the location of the repository. pserver is the login method, the first anonymous is the password, and the second anonymous is the username. You'll be accessing the repository at cvs.drupal.org, within the /cvs/drupal-contrib folder. In the example path above, *modules* can also be *themes*, *translations*, or even *profiles*.
It's important to note that sometimes the contributions/modules/name_of_contrib_module path listed above can be several levels deep, as in modules/ecommerce/* rather than just modules/views.
For example paths and project names, Browse the list of contrib modules or contrib themes on cvs.drupal.org.
All contributions at once
To check out all contributions at once, which is highly discouraged as the contributions repository is huge and checking it all out puts a major stranglehold on the drupal.org servers, cd your way to the root of the directory you wish to save to and type:
// Checkout the entire contrib repository:
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout contributionsCheck out a contrib project into a specific directory
It's often useful to check out a contrib module or theme into a specific directory rather than the full contrib path. That allows you to, for instance, pull a single module directly from CVS into a multi-site's sites/example.com/modules directory. To do so, use a command such as the following:
cd sites/example.com/modules
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout -d modulenamehere contributions/modules/modulenamehereCheck out all contributions for a certain Drupal version
To check out the contributions directory for a certain Drupal version, do
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout -r <version tag> contributionswhere
<version tag> is build up according to the Drupal version tags
Checking out a specific version of a contrib module
To target a selected version of a module, such as moduleName_5.x-1.x-dev, do
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout -r DRUPAL-5--1-0 -d moduleName contributions/modules/moduleNameThe DRUPAL-5--1-0 number is one of the available NON-BRANCH tags found on the Sticky Tag dropdown list at the top of the CVS contrib modules repo.
Contributing your own code:
If you're looking to add your own modules, themes, translations TO the repository, the Maintaining a project on drupal.org page has a useful introduction to getting started, while the Maintainer quick-start guide provides an easy reference to useful CVS commands.

Tag listing
The only tags listed as "Non-branch tags" there are "navlinks" and "HEAD"
For
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout -r <version tag> -d moduleName contributions/modules/moduleNameThe tags that seem to work are things like DRUPAL-5--1-0 or DRUPAL-6--1-0 DRUPAL-6--1-1 etc.
**Edit: Oh ok you have to descend into the directories to get the proper tag listings :D