Simple Widgets
Label Label widget with state option, dynamic help and drag and drop facilities
Entry Entry widget with state option, dynamic help and drag and drop facilities
Button Button widget with enhanced options
ArrowButton Button widget with an arrow shape.
ProgressBar Progress indicator widget
ScrollView Display the visible area of a scrolled window
Separator 3D separator widget

Manager Widgets
MainFrame Manage toplevel with menu, toolbar and statusbar
LabelFrame Frame with a Label
TitleFrame Frame with a title (consider Tk 8.4+ labelframe instead)
PanelFrame Frame with a boxed title area
ScrolledWindow Generic scrolled widget
ScrollableFrame Scrollable frame containing widget
PanedWindow Tiled layout manager widget (consider Tk 8.4+ panedwindow instead)
ButtonBox Set of buttons with horizontal or vertical layout
PagesManager Pages manager widget
NoteBook Notebook manager widget
Dialog Dialog abstraction with custom buttons
StatusBar Status bar widget with resize control

Composite Widgets
LabelEntry LabelFrame containing an Entry widget.
ComboBox ComboBox widget
SpinBox SpinBox widget (consider Tk 8.4+ spinbox instead)
Tree Tree widget
ListBox ListBox widget
MessageDlg Message dialog box
ProgressDlg Progress indicator dialog box
PasswdDlg Login/Password dialog box
SelectFont Font selection widget
SelectColor Color selection widget

Commands Classes
Widget The Widget base class
DynamicHelp Provide help to Tk widget or BWidget
DragSite Commands set for Drag facilities
DropSite Commands set for Drop facilities
BWidget Description text