With OS X Yosemite's new look this project is now obsolete, I don't recomend using It anymore.
Check out GRVibrantTitlebarWindow!
A NSWindow subclass with a beautiful glass-like title bar.
Use the sample app and headers as a guide, more documentation coming soon.
Thank you Raffael for the challenge.
You can contribute with code, just send me a pull request, or open an issue for any bug/enhancement.
Disclaimer: sending a pull request does not mean I will accept It, if I don't accept your pull request It doesn't mean I don't love you ;)
If you like this and will use It to make your app look like one of Jony Ive's really sexy creations, you can show me some love by donating through PayPal