Lost and Found: What is GNU?

Well, I just found out, or shall I say rediscover the meaning ofGNU. All I could remember about it is the recursive acronym part. GNU is Not something. Well, I found it today. GNU is Not Unix. =D

Also had quite a bit of education in accounting AND difference between Open Source, Free Software and a whole multitude of different types of licenses. Whew, it's all so confusing.