I don't think dynamic scoping makes it possible -- I think it is used simply because it is there. If it wasn't there, some other solution, just as good (if not

I don't think dynamic scoping makes it possible -- I think it is used simply because it is there. If it wasn't there, some other solution, just as good (if not better) would be used. When writing e-lisp, I find dynamic scoping limiting, and using lexical-let, especially when I want curried/partial-application, is extremely annoying. For me, extending emacs is harder because of dynamic scoping. It is entirely possible to have code be executed in some sort of "Reader" monad/env, and execute it in a different than default env -- which gives you "dynamic scoping" on whatever input you want, without contaminating every other name. I think almost every negative feature you could possibly implement would find "good use" that defended its existence (Dynamic scoping, $_ in Perl, implementation inheritance, etc).