Open Atrium's code is open, meaning that anyone can do anything with the code base. You can play with it, use it as is, build on it to make it what you need, package it up and sell it to your clients, or start a hosted service with it. You name it, you can do it.
Since Open Atrium is completely open, we can all work together on it to make it better. Here are a few ways that you can get involved with the project:
Open Atrium is built on Drupal. This makes it easy to add other Drupal modules to the package and to build new features for it. But because of this, some issues, bugs, and functionality requests for Open Atrium are dependent on Drupal.org and not on Open Atrium alone. If you don't have one already, go create an account on Drupal.org. This will let you fully participate in issue queues and other conversations about the bits of Open Atrium based in Drupal.
Documentation and Community.OA
A new documentation site for Open Atrium 2.0 is coming! For Open Atrium 1.0 (on Drupal 6), all of the community driven documentation as well as the issue tracker for the project is at https://community.openatrium.com.
Translate Open Atrium
When we announced that Open Atrium was on the way, we immediately got a ton of offers to translate it into other languages. So we set up a translation service to make this possible and easy. We have since migrated to use localize.drupal.org to manage all translations.
To translate Atrium into a language you know, go to localize.drupal.org, set up an account, and join your language group. You'll have the opportunity to not only help translate Open Atrium's Features but Drupal as well.
We have and IRC channel,
irc.freenode.net, for talking about Atrium. This isn't as much a support forum as it is a place to talk about developing and using Atrium.