Ahh, Forth.
It must have been ten years ago that I tried to explain the essence of Smalltalk to my brother, a Forth programmer. We found common ground by programming -- one day in Forth, another in Smalltalk. In Forth we wrote the essential Smalltalk: object identity and method dispatch; in Smalltalk we wrote the essential Forth: dictionary, words and builds-does. We both showed off our respective environments with great skill, pride and confidence. Oh, if only all programming could be so educational. -- WardCunningham
See also: SmalltalkInForth, SmalltalkLanguage and ForthLanguage.