There is now a quick reference card for the tk widgets here.
In the wish interpreter, the following commands are added above and beyond those provided by tcl:
after.n bell.n bind.n bindtags.n bitmap.n button.n canvas.n checkbutton.n clipboard.n destroy.n dialog.n entry.n exit.n fileevent.n focus.n focusNext.n frame.n grab.n image.n label.n license.terms listbox.n lower.n man.macros menu.n menubar.n menubutton.n message.n option.n optionMenu.n options.n pack-old.n pack.n palette.n photo.n place.n popup.n radiobutton.n raise.n scale.n scrollbar.n selection.n send.n text.n tk.n tkerror.n tkvars.n tkwait.n toplevel.n update.n winfo.n wish.1 wm.n
The following C callable routines are provided in libtk.a:
3DBorder.3 BackgdErr.3 BindTable.3 CanvPsY.3 CanvTkwin.3 CanvTxtInfo.3 Clipboard.3 ClrSelect.3 ConfigWidg.3 ConfigWind.3 CoordToWin.3 CrtErrHdlr.3 CrtGenHdlr.3 CrtImgType.3 CrtItemType.3 CrtMainWin.3 CrtPhImgFmt.3 CrtSelHdlr.3 DeleteImg.3 DoOneEvent.3 DoWhenIdle.3 DrawFocHlt.3 EventHndlr.3 EventInit.3 FileHndlr.3 FindPhoto.3 FreeXId.3 GeomReq.3 GetAnchor.3 GetBitmap.3 GetCapStyl.3 GetClrmap.3 GetColor.3 GetCursor.3 GetFontStr.3 GetGC.3 GetImage.3 GetJoinStl.3 GetJustify.3 GetOption.3 GetPixels.3 GetPixmap.3 GetRelief.3 GetRootCrd.3 GetScroll.3 GetSelect.3 GetUid.3 GetVRoot.3 GetVisual.3 IdToWindow.3 ImgChanged.3 InternAtom.3 MainWin.3 MaintGeom.3 ManageGeom.3 MapWindow.3 MoveToplev.3 Name.3 NameOfImg.3 OwnSelect.3 ParseArgv.3 Preserve.3 Restack.3 RestrictEv.3 SetAppName.3 SetClass.3 SetGrid.3 SetVisual.3 Sleep.3 StrictMotif.3 TimerHndlr.3 Tk_Main.3 WindowId.3