Here is an interesting blurb I found around the interweb. During the development of Microsoft Windows XP, the team responsible for the user interface was super cloak-and-dagger on how the final look of the UI would look alike. They wanted to make a splash for the upcoming E3 2001.
On the other hand, the programmers who were setting up the infrastructure for visual styles needed to have something to test their code against. And something had to go out in the betas.
The visual styles team came up with two styles. In secret, they worked on Luna. In public, they worked on a “decoy” visual style called “Mallard”. (For non-English speakers: A mallard is a type of duck commonly used as the model for decoys.) The ruse was so successful that people were busy copying the decoy and porting it to their own systems. (So much for copyright protection.)
courtesy The Old New Thing.