Mac - iTunes status indicator thing

I don't know what to call it, but you know that greenish thing covering most of the middle of the top of the iTunes window, that shows the apple symbol or shows the music slider or the status etc开发者_开发知识库., what is it? I've seen several other applications using it -- how do you get it? I couldn't find it in Interface Builder.

Thanks.

---

It's not available as a standard component (yet). iTunes is not even a Cocoa app (well, some part of it is Cocoa, but not much.). A few other Apple apps have similar interface element, so let's hope it'll become available in the next version.