Docs can be found at
2002-06-21 - Marty Backe's example of displaying a file in a text widget:
package require Iwidgets iwidgets::scrolledtext .t pack .t -fill both -expand true set filename "readme.txt" .t import $filename end
HJG 2016-02-07: It looks like there are problems with Iwidgets.
With tcl 8.6, this example just crashes.
With tcl 8.5, it crashes when the file doesn't exist.
Also, that screenshot at sf.net exists, but doesn't show up.