On the download page we offer complete installable packages of Open Atrium. These packages are the quickest and easist way to install Open Atrium, using them is highly recommended.
However it is also possible to assemble Open Atrium yourself using the same process we use. Open Atrium is a Drupal install profile and which lives on drupal.org. Our install profile references many Drupal modules and other projects, so we use
Drush make build system to pull all the code together into one package. Instructions to do this are maintained our [community site].