Wow, a couple of years ago it would have seemed unthinkable that a company like EA would release some of their code as open source. Only very few major game companies released code back then (I can think of only id and Insomniac).
Some of us our trying to turn that around. My studio, EA2D, has a lot of people from the startup space, so sharing is only natural. We have a small but quickly growing list of open source projects (many more in the pipeline):
It took ages for us to get the approvals for it, but the Star Wars: The Old Republic web team can now push our patches and custom modules for Drupal back to that community, too.