Toolbar is a pretty common term. So the reader should not be surprised if they find various ways of creating such a thing.
For instance, Iwidgets has a toolbar command:
Docs can be found at http://incrtcl.sourceforge.net/iwidgets/iwidgets/toolbar.html and http://purl.org/tcl/home/man/iwidgets3.0/toolbar.n.html
http://www.iit.demokritos.gr/~petasis/Tcl/toolbar.tcl provides dockable toolbars. See also ClassyTk (and mkImagesPane for code that could be used to create a toolbar).
Bwidget has a MainFrame widget, which includes a toolbar created as a ButtonBox (a series of Bwidget buttons).
Category Command, a part of incr Widgets