Here are GNU sed commands for typo fixes for the .tcl files.

sed -i "s/dialogs/dialogues/g" bwidget/utils.tcl
sed -i "s/existance/existence/g" bwidget/entry.tcl
sed -i "s/informations/information/g" bwidget/listbox.tcl
sed -i "s/perferct/perfect/g" bwidget/widget.tcl
sed -i "s/substract/subtract/g" bwidget/notebook.tcl

If it's desired to edit the ChangeLog here are the fixes.

sed -i "s/Disfunction/Dysfunction/g" bwidget/ChangeLog
sed -i "s/appearence/appearance/g" bwidget/ChangeLog
sed -i "s/dialogs/dialogues/g" bwidget/ChangeLog
sed -i "s/enless/endless/g" bwidget/ChangeLog
sed -i "s/horizantal/horizontal/g" bwidget/ChangeLog
sed -i "s/incompatabilities/incompatibilities/g" bwidget/ChangeLog
sed -i "s/paramters/parameters/g" bwidget/ChangeLog
sed -i "s/reagion/region/g" bwidget/ChangeLog

If it's desired to edit CHANGES.txt.

Is displacement rather than deplacement the intention here?

$ sed -n '708,710p' bwidget/dynhelp.tcl
        # Increment the required size by the deplacement from the passed point
        incr width 8
        incr height 12
$

If displacement is correct this would be the fix.

sed -i "s/deplacement/displacement/g" bwidget/dynhelp.tcl

Is unknown-time rather than unknow-time the intention here?

$ sed -n '164p' bwidget/CHANGES.txt
    - now can be incremental or not limited ('unknow-time' processing)
$ 

If unknown is correct then this would be the fix.

sed -i "s/unknow/unknown/g" bwidget/CHANGES.txt

Here are other typos in CHANGES.txt.

sed -i "s/completly/completely/g" bwidget/CHANGES.txt
sed -i "s/incompatibilites/incompatibilities/g" bwidget/CHANGES.txt
sed -i "s/optionnal/optional/g" bwidget/CHANGES.txt
sed -i "s/painfull/painful/g" bwidget/CHANGES.txt
sed -i "s/retreive/retrieve/g" bwidget/CHANGES.txt