Are there any current projects that will work in squeak5.1/spur that can draw nice graphs?
I'm answering this just for the record, because I think it's overkill, but there is extensive graphing capability in muO.
For example, the one-liner
(NFunction histogram: #(5 10 15 26 12 30 10 20 25 3) origin: 0 delta: 1) display
produces the attached display.
Stef