On the US governmental note, ACE is a big proponent source and due to the tight security that they need to run, they use Linux a lot and have released lots of good code into the open source ecosystem (the biggest one being GRASS). They're also the biggest user of the speex codec.
If you have an apple and I have an apple and we exchange these apples then you and I will still each have one apple. But if you have an idea and I have an idea and we exchange these ideas, then each of us will have two ideas.
George Bernard Shaw