The GNU Song, or simply The Gnu, was released in 1960 by Flanders and Swann.
There are several instances of this song on YouTube, this one shows gnice pictures of gnatural GNUs and even one of Richard Stallman:
You can read the text here:
The GNU Song on Flanders' and Swann's official Website
And if you want to download it and own it legally:
Flanders and Swann have thoroghly provided evidence that GNU should be pronounced with an audible G.
Agnother reason is that only with a clear G, the word can be distinguished from new.
This assertion is also well grounded on ethymology: The word derives from the South-African Khoikhoi language and resembles the grunting sound the animal makes when it is chewing grass. Indeed, GNU sounds much like gnaw.

No arguing with that. But, indeed, this website is coded using TPYO3, which is released under the terms of the GNU General Public Licence (GPL). Moreover, some project related documents, or parts of them, are made using software distributed under the GPL as well. Copyright for the GNU head: Free Software Foundation, Inc.
GNUs usually prefer a warm climate and rather flat landscapes, but there are exceptions.
GNU may be a scary project, but not the only one.
GNU for people with nerves of steel
And, likewise,
GMES is not GMES.

Begegnung: people getting together (what GNU is about)
Eignung: suitability (of GNU results to help optimise GMES)
Entgegnung: answer (which GNU provides to solve certain problems)
Vergnuegen: delight (which you will feel when you read our reports)

Although the statement that a GNU looks like a mixture of a cow and a horse appears a bit innocent, the Wikipedia is, als usual, quite a good place to start your search.

The logo for our project was created by FABIANDESIGN. Within GMES, GNU is a different kind of animal (or project), which is expressed by this different kind of logo.