One diffrence is these data flow stuff threw the code. I have not seen that anywhere else. There are some otherthing that are diffrent. The way they want to handle files for example.

I would say that Light Table is nothing revolutionary but it is long awaited evolutionary. Finally a modern envoierment that is really easibly extensible.

Emacs is great but you have to admit that it is truly aged. Things like eclipse are diffrent from these dynamic smalltalk IDEs that LT trieds to be like (without having the same weaknesses).