Smalltalk also has similar interactive development styles. One can build the application incrementally piece-by-piece. It has a residual graphical integrated development environment -> the development environment is a part of the program. It uses late-binding via message-passing. It starts and saves images (-> dumps of the heap contents, data and code). It is introspective & reflective (one can find out about the running program and can change it).
READ mostly gives a tree of tokens. This makes it a form of a tokenizer. After we call READ we don’t know what the tokens mean: is FOO a variable, a macro, a function, a built-in special form, a type, … This can only be determined by interpreting/compiling the token tree.