GenericToolbar was a toolbar palette for Interface Builder 2, which was made obsolete in 2007 when Apple released Interface Builder 3.
If you still have projects which use GenericToolbar, you can switch to using standard toolbars using the converter plug-in below. Import options are configurable from Interface Builder's preferences.
The old GenericToolbar package contains an Interface Builder 2 palette and a set of classes to include in your project, most notably the NSCoding-compliant subclasses of NSToolbar and NSToolbarItem. The DragMatrix class used extensively in the palette was created by Sailesh Agrawal. Note that this may create a problem if you try to make a (different) class called DragMatrix and use it in IB.
Thanks to Sailesh Agrawal for DragMatrix, and also to Dave Dribin for catching a slew of bugs in the original palette.