Hello Tobias
please read this article:
http://wiki.lazarus.freepascal.org/Carbon_Interface#Cocoa_controls_in_Carbon_applications
If you mange to do this steps successfully and you have Carbon LCL recompiled with Cocoa support, then you can use TTrayIcon component.
One more note. If you mark TTrayIcon.Visible = True in Object Inspector, this will show the icon, but sub-menu won't appear (for some reason).
To fix this, you need to change TTrayIcon visibility in run-time, for example in FormCreate event:
procedure TForm1.FormCreate(Sender: TObject);
begin
TrayIcon1.Visible:=true;
end;
this will make both: Tray icon visible in OSX Status Bar, and sub menu working.
thanks,
dmitry