Hello and thank you for such a valuable program.
I have made some enhancements to the XTherion GUI, mainly to facilitate
single-click editing (most editing actions require two or more mouse
clicks without counting scrollbar clicks, while shortcut keys require
that you take your hands off the mouse while tracing a cave sketch with
it).
Here is a screenshot of how XTherion looks with the changes on winXP:

As seen, a toolbar with a number of icons has been added, together with
a few changes to the skin of the Tk widgets. Tk for windows has still
rather ancient looks, but Therion does not deserve this.
Actually the proper place for the editting icons would rather be under
the "File commands" pane, as a replacement of the various buttons
there, but the auto-scroll feature of the panel makes this pane hide
very often, so putting them there under these circumstances would
defeat the purpose.
I have also made a number of other icons for XTherion that fit in other
panes and might include them in there if I find a way to stop
autoscrolling and eliminate inactive panes from the panel.
Of course I will share this code with anyone, if there is interest.
Forgot to say, I have just completed my first ever cave map with this
wonderful program (that is, I am a newbie in cave surveying).
Hopefully, I can now be accepted to Plato's Academia ;-)
Dimitrios