OS X utilities provide several plugin calls for OS 10 features, including executing command line programs as the superuser ("root"), drawing into the dock icons of your application or a window, getting unix information about a file (such as its path), working with the preferences menu item, and more.
Version 1.1 should fix some compatibility problems with OS 10.1; support is no longer provided nor claimed for OS 10.0. Dock drawing should also be faster; workarounds included in previous versions were necessary because of bugs in 10.0 that are fixed in 10.0.
MacOS X 10.0 or later
*Previously available here