Open Atrium
What is Open Source?
Open Atrium is completely open source (licensing details here). Why? Because for Open Atrium to be one of the best collaboration tools out there, the teams using it need to have full control over how it works.
Most of Open Atrium's code base is GPL v. 2, inherited from Drupal, the open source platform that's the backbone of the package.
Open Atrium is completely open source. Why? Because for Open Atrium to be one of the best collaboration tools out there, the teams using it need to have full control over how it works.
Most of Open Atrium's code base is GPL v. 2, inherited from Drupal, the open source platform that's the backbone of the package. Pieces that aren't specifically Drupal - like the themes that Open Atrium comes with - are licensed under BSD.
For those who are new to open source, the story goes something like this. In what is seen as the most productive reaction in history to being pissed off at an office printer, Richard Stallman started the free software movement (among other things) to promote the right for people to be able to modify software, rather than be stuck with proprietary software with restrictive licensing.

Drupal is a killer open source content management framework that's easy to modify and has a user base of hundreds of thousands of people. It got its start in the dorm room of Dries Buytaert, where he released the code to a little PHP content management system that he was working on with friends. The rest is history. The very active community that Dries helped bring together is flying today, with an estimated 240,000 websites powered by Drupal 6. Open Atrium is one, being built on Drupal 6 core.
Six years ago when Development Seed got its start in the mountains of Peru, Drupal looked like a great framework to help international development organizations collaborate online. Drupal has treated us well, and over the years we've attracted a team that wants to change the world by building powerful open source projects. One way we do this is to make sure all our work is open so it has the biggest impact possible. Open Atrium is one of our most recent projects.