Newbie wants to get visual

[MartinRinehart at gmail.com]

I'm ready to start coding the parser for my Decaf (beginners)
language. I think that a "visual" parser (one that shows what it's
doing as it does it) would be nice. (And I think that it would help
the parser author by saving the requirement for a bazillion print
statements while debugging the tool.)

Can someone point me toward the easiest possible way to get GUI? I've
got the Rappin/Dunn book re wxPython, but suspect that this may be
overkill for what I want. If I could do something that would work in a
browser window, that would be wonderful.