More to the point, every icon in the menu bar except for Spotlight can be turned on or off in the System Preferences. If hunting down those checkboxes is too much work, you can also Command-click on any of Apple’s icons [0] and drag them out of the menu bar. This also allows you to rearrange icons. (That works also for buttons on toolbars.)
[0] I only have one third-party icon in my menu bar (Dropbox) and it can’t be dragged out of the menu bar. I don’t know whether that’s the case for all third-party icons.
I only have one third-party icon in my menu bar (Dropbox) and it can’t be dragged out of the menu bar. I don’t know whether that’s the case for all third-party icons.
It is. Apple has their own private API for their "menu extras" and actually loads them into the windowserver itself. It's a major PITA to support one of these things, so only a very small number of third party apps choose to do it.
The alternative public API is basically just a tiny window for each item sitting in the menubar. There's no technical reason why Apple couldn't implement the same kind of command-drag behaviour, but thus far they haven't.
