Pharo and other Smalltalks are definitely interactive in the sense that I mean. Factor, too, as far as I know, and I'd add FORTH, though Lisp and Smalltalk syst

Pharo and other Smalltalks are definitely interactive in the sense that I mean. Factor, too, as far as I know, and I'd add FORTH, though Lisp and Smalltalk systems tend to have more high-level conveniences than FORTH systems I've worked with. I don't know whether the others you mention are or not. A reasonable litmus test is: define some data structure and make a bunch of instances of it. Now redefine the data structure. What happens to the existing instances? Does the runtime automatically notice that the structure definition has changed and offer you a way to update the existing instance to comply with the new definitions? Another is to write a function that intentionally contains a call to some other nonexistent function, then call it. What happens when you hit the undefined function? Are you offered an interactive session that you can use to grovel around in the dynamic environment of the suspended function call? Can you see all the parameters and locals on the stack? Can you edit their values? Redefine types and pending functions? Can you supply the missing function definition, resume the suspended function call, and reasonably expect it to return a value as if the function in question had been defined all along? If the answers are yes, then the language runtime is interactive "in the bones", in the sense I mean. If not, then not so much.