Could a Lisp be Blub?
jerf: How could you cripple such things? Well, first, culture. The primary difference between Ruby and Python is culture; the languages enable virtually identical styles of programming in practice (spelled slightly differently, but basically the same), but the cultures encourage different practices, such as how they feel about monkeypatching. Neither of these cultures "cripples" the language, I just use this as an example of the power of culture. You could cripple a powerful language with some sort of powerful pedagogical culture that made the powerful idioms verboten (because they're "too complicated", "unmaintainable", etc.).A good language should make the right thing easier than the wrong thing. You could cripple a language that has all those bullet-point features by making putting hoops to jump through in the way of using macros or first-class functions. A klunky syntax, some sort of extra typing information to be manually added at every macro invocation, extra-verbose S-expressions, etc.A REPL could be crippled by making it less than a full REPL, such that there are things that you still have to build modules for. See Erlang's REPL, which is mostly nice, except you can't define new records or do a handful of other useful things.The most likely way this could happen is a language that tries to be LISP while still looking as much like C(++/#) as possible, and bringing over impedance-mismatched concepts better left in C(++/#). The second-most likely would be in some way constraining the power so as not to scare programmers or so as to avoid some "trap"; for instance, see Java's dropping of multiple inheritance. Thus, even though Java has "OO", it is less powerful than a Java that had MI too. You might have a "first class function" that is somehow limited to be less useful. (Perhaps you get first-class functions, but themselves are not allowed to return functions, only "values".)Do not underestimate the power of language implementors to cripple a language, both intentionally and otherwise.